feat(model,capacity,vision,io): per-persona 路由 + 本地三级(默认关) + L3 分类 + OCR 独立模型 + image-crop 工具（裁决 03.4.1/03.4.3/14.4.1/14.4.4/14.4.5）

- 03.4.1：per-persona 路由载体选 models.json（组内新增 personaModels/personaProviders + 校验 + PersonaRoute()），
  Router/RuntimeLLM 快照绑定、loop 流式路径按该 turn 的 persona 路由；主步用路由结果、降级步钉自己的模型
- 03.4.3：本地第三级降级链（LLM_LOCAL_*，Configured() 含 Enabled ⇒ **默认关**），warn 标注来源
- 14.4.4：capacity 接入 L3（分类器接口 + TTL 缓存 + 严格 JSON 解析），CAPACITY_L3_ENABLED **默认 false**
- 14.4.1：语义修正 —— group.multimodal 才是「主模型能否收图」（env 路径不再臆断），LLM_VISION_MODEL 只配视觉工具；
  vision/OCR 可各用不同模型；runtime 不再因有图抢路由（vision.Router 是唯一分层权威）
- 14.4.5：新增 image-crop 工具（工具数 5→6，策略默认 owner-only），schema 支持按区域裁切
- 组合根：wire_runtime 读 group.Multimodal；capacity 装配拆出 wire_capacity.go（守 500 行）
- 复核：`go build`/`go vet`/各包 `go test -count=1` 全绿；**6 条变异反证**先红后还原（含作者自查出的 2 条假阳性变异）
- 未落：按 provider 的 thinking 开关（需 openai_encode.go/openai.go 文件面）、persona awakening（需 loader 文件面）

cmd/cyrene/wire_capacity.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"strings"
+	"time"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/capacity"
+)
+
+// 本文件拥有唤醒式能力（capacity）决策层的装配：判定器构造、工具集 JSON 解析、
+// L3 缓存 TTL 解析与 capacity_awaken 事件出口。它从 wire_runtime.go 拆出
+// （AGENTS §10 文件 ≤500 行；wire.go 拆分建议同样适用于本文件）。
+
+// buildCapacity constructs the awakened-capacity decider when enabled, or nil
+// (which keeps the loop's default all-tools behavior). It is opt-in via
+// CAPACITY_ENABLED; the allowed-set mapping comes from CAPACITY_TOOL_SETS and
+// falls back to built-in defaults on a parse error.
+//
+// The model-assisted L3 layer (裁决 14.4.4) is a second, independent switch
+// (CAPACITY_L3_ENABLED, default false): even with capacity on, L3 stays silent
+// unless it was explicitly asked for, and its verdict cache TTL
+// (CAPACITY_L3_CACHE_TTL, default 5m) is parsed here because the config loader
+// only carries scalars.
+func (a *app) buildCapacity() *capacity.Decider {
+	if !a.cfg.Capacity.Enabled {
+		return nil
+	}
+	sets, err := parseCapacityToolSets(a.cfg.Capacity.ToolSetsJSON)
+	if err != nil {
+		a.log.Warn("capacity tool sets parse failed, using built-in defaults", "error", err)
+		sets = nil
+	}
+	cfg := capacity.Config{
+		Enabled:       true,
+		MinConfidence: a.cfg.Capacity.MinConfidence,
+		ToolSets:      sets,
+	}
+	if a.cfg.Capacity.L3Enabled {
+		cfg.L3Enabled = true
+		cfg.L3Classifier = capacity.NewLLMClassifier(a.modelAdapter, a.log)
+		cfg.L3CacheTTL = parseL3CacheTTL(a.cfg.Capacity.L3CacheTTL, a.log)
+	}
+	return capacity.New(cfg, capacity.WithLogger(a.log))
+}
+
+// parseL3CacheTTL parses the CAPACITY_L3_CACHE_TTL duration string. An empty
+// value selects the code default (5m, the landing suggestion of 裁决 14.4.4); an
+// unparsable value is reported and falls back to the same default rather than
+// silently disabling the cache.
+func parseL3CacheTTL(raw string, log *slog.Logger) time.Duration {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return capacity.DefaultL3CacheTTL
+	}
+	d, err := time.ParseDuration(raw)
+	if err != nil {
+		logger.WithSource(log, "cmd/cyrene").Warn("capacity L3 cache ttl unparsable, using the default",
+			"value", raw, "default", capacity.DefaultL3CacheTTL.String(), "error", err)
+		return capacity.DefaultL3CacheTTL
+	}
+	return d
+}
+
+// parseCapacityToolSets decodes the CAPACITY_TOOL_SETS JSON map of
+// state→allowed tool name list. A blank string yields nil (built-in defaults); a
+// null value for a state means unrestricted (all tools).
+func parseCapacityToolSets(raw string) (map[capacity.State][]string, error) {
+	if strings.TrimSpace(raw) == "" {
+		return nil, nil
+	}
+	var m map[string][]string
+	if err := json.Unmarshal([]byte(raw), &m); err != nil {
+		return nil, fmt.Errorf("capacity tool sets: %w", err)
+	}
+	out := make(map[capacity.State][]string, len(m))
+	for k, v := range m {
+		out[capacity.State(k)] = v
+	}
+	return out, nil
+}
+
+// onCapacity is the loop's OnCapacity sink: it observes a capacity_awaken
+// transition and pushes it to the Web UI (design/14 §5) as a `capacity_awaken`
+// frame. The loop only emits on a real state transition (never every round), and
+// the event carries the originating session id so it routes to that session, not
+// globally. The payload is the frontend AwakenPayload {fromState,toState,tool}.
+func (a *app) onCapacity(ev capacity.Event) {
+	logger.WithSource(a.log, "cmd/cyrene").Debug("capacity event",
+		"type", ev.Type, "from", ev.FromState, "to", ev.ToState,
+		"tool", ev.Tool, "at", ev.At, "session", ev.SessionID)
+	if a.capacitySink == nil {
+		return
+	}
+	a.capacitySink.BroadcastCapacityAwaken(ev.SessionID, string(ev.FromState), string(ev.ToState), ev.Tool)
+}

cmd/cyrene/wire_runtime.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"path/filepath"
 	"strings"
@@ -15,7 +14,6 @@ import (
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/persona/loader"
 	personareg "git.yeij.top/AskaEth/Cyrene_v2/internal/persona/registry"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/agent"
-	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/capacity"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/embedding"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/guardrail"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
@@ -191,8 +189,14 @@ func (a *app) wireRuntime() error {
 	}
 
 	// Vision routing: the loop rewrites an image-bearing user message per the
-	// vision Router — a vision-capable main model sees the image directly,
+	// vision Router — a main model that really accepts image input sees the image
-	// otherwise the vision/OCR tool's text description replaces it (design/06 §0).
+	// directly, otherwise the vision/OCR tool's text description replaces it
+	// (design/06 §0)。
+	//
+	// SupportsVision means "主模型能否收图"（裁决 14.4.1 修语义，C-7）, read from the
+	// active models.json group's `multimodal` declaration — NOT from
+	// LLM_VISION_MODEL, which configures the vision *tool's* model. It is read per
+	// call so a panel save/reload takes effect on the next turn.
 	visionRouter := vision.NewRouter(
 		vision.WithVisionTool(visionToolName),
 		vision.WithOCRTool(ocrToolName),
@@ -200,7 +204,8 @@ func (a *app) wireRuntime() error {
 	visionResolver := vision.NewMessageResolver(
 		visionRouter,
 		func() vision.ModelInfo {
-			return vision.ModelInfo{Name: a.cfg.LLM.VisionModel, SupportsVision: a.cfg.LLM.VisionModel != ""}
+			group := a.llm.Group()
+			return vision.ModelInfo{Name: group.Model, SupportsVision: group.Multimodal}
 		},
 		a.dispatcher.Invoke,
 	)
@@ -374,40 +379,8 @@ func (a *app) approvalActor(ctx context.Context) string {
 	return pid
 }
 
-// buildCapacity constructs the awakened-capacity decider when enabled, or nil
+// buildCapacity / onCapacity / capacity JSON+TTL parsing live in
-// (which keeps the loop's default all-tools behavior). It is opt-in via
+// wire_capacity.go (AGENTS §10 文件 ≤500 行).
-// CAPACITY_ENABLED; the allowed-set mapping comes from CAPACITY_TOOL_SETS and
-// falls back to built-in defaults on a parse error.
-func (a *app) buildCapacity() *capacity.Decider {
-	if !a.cfg.Capacity.Enabled {
-		return nil
-	}
-	sets, err := parseCapacityToolSets(a.cfg.Capacity.ToolSetsJSON)
-	if err != nil {
-		a.log.Warn("capacity tool sets parse failed, using built-in defaults", "error", err)
-		sets = nil
-	}
-	return capacity.New(capacity.Config{
-		Enabled:       true,
-		MinConfidence: a.cfg.Capacity.MinConfidence,
-		ToolSets:      sets,
-	}, capacity.WithLogger(a.log))
-}
-
-// onCapacity is the loop's OnCapacity sink: it observes a capacity_awaken
-// transition and pushes it to the Web UI (design/14 §5) as a `capacity_awaken`
-// frame. The loop only emits on a real state transition (never every round), and
-// the event carries the originating session id so it routes to that session, not
-// globally. The payload is the frontend AwakenPayload {fromState,toState,tool}.
-func (a *app) onCapacity(ev capacity.Event) {
-	logger.WithSource(a.log, "cmd/cyrene").Debug("capacity event",
-		"type", ev.Type, "from", ev.FromState, "to", ev.ToState,
-		"tool", ev.Tool, "at", ev.At, "session", ev.SessionID)
-	if a.capacitySink == nil {
-		return
-	}
-	a.capacitySink.BroadcastCapacityAwaken(ev.SessionID, string(ev.FromState), string(ev.ToState), ev.Tool)
-}
 
 // onToolAudit is the loop's OnAudit sink: it forwards a tool call denied by the
 // design/11 §3 security gate in a group/stranger environment into the gateway
@@ -424,23 +397,7 @@ func (a *app) onToolAudit(ev loop.AuditEvent) {
 	a.gw.AuditEvent(ev.Who, ev.What, ev.Result)
 }
 
-// parseCapacityToolSets decodes the CAPACITY_TOOL_SETS JSON map of
+// parseCapacityToolSets / parseL3CacheTTL live in wire_capacity.go.
-// state→allowed tool name list. A blank string yields nil (built-in defaults); a
-// null value for a state means unrestricted (all tools).
-func parseCapacityToolSets(raw string) (map[capacity.State][]string, error) {
-	if strings.TrimSpace(raw) == "" {
-		return nil, nil
-	}
-	var m map[string][]string
-	if err := json.Unmarshal([]byte(raw), &m); err != nil {
-		return nil, fmt.Errorf("capacity tool sets: %w", err)
-	}
-	out := make(map[capacity.State][]string, len(m))
-	for k, v := range m {
-		out[capacity.State(k)] = v
-	}
-	return out, nil
-}
 
 // dbCfgForEmbed returns the DB config used by the vector index, which opens the
 // same SQLite file as the primary pool.

internal/config/config.go

@@ -88,10 +88,23 @@ type LLMConfig struct {
 	Model    string `env:"LLM_MODEL"`
 	Fallback string `env:"LLM_FALLBACK_MODEL"`
 
-	// VisionModel is the dedicated model used for image/vision requests. When
+	// VisionModel is the dedicated model behind the vision tool (image
-	// set, the model router routes image content to it (see model.Router.WithVisionModel).
+	// understanding). It is the tool's model, not the main model's ability: the
+	// per-persona/per-request routing decision belongs to the vision Router, and
+	// the main model's own image input capability is declared by the active
+	// models.json group's multimodal flag (裁决 14.4.1/14.4.5)。
 	VisionModel string `env:"LLM_VISION_MODEL"`
 
+	// OCRModel is the dedicated model behind the OCR tool. Empty reuses
+	// VisionModel, so OCR keeps working without a second endpoint (裁决 14.4.1
+	// 的「独立视觉模型 + OCR 模型」)。
+	OCRModel string `env:"LLM_OCR_MODEL"`
+
+	// Local is the optional third degradation level (裁决 03.4.3): primary →
+	// fallback → local. It defaults to off because the current machine cannot run
+	// a local model comfortably; when off the chain keeps its two-level shape.
+	Local LocalLLMConfig
+
 	// FallbackMaxTokens caps the last-resort fallback model in a group's chain
 	// (primary → fallback). It is the final safety budget: it only applies when
 	// the chain actually has a fallback step, that group sets no per-group
@@ -107,6 +120,33 @@ type LLMConfig struct {
 	AnthropicFallback string `env:"ANTHROPIC_FALLBACK_MODEL"`
 }
 
+// LocalLLMConfig configures the optional local model rung — the third level of
+// the primary → fallback → local degradation chain (裁决 03.4.3). It is opt-in
+// and defaults to off: a machine that cannot run a local model comfortably must
+// not silently pay for one. It becomes an active chain step only when Enabled is
+// true and both BaseURL and Model are set; anything less is reported and skipped
+// rather than producing a half-configured step.
+type LocalLLMConfig struct {
+	// Enabled turns the local rung on. Default false (project red line: 本地模型可开关，默认关).
+	Enabled bool `env:"LLM_LOCAL_ENABLED" default:"false"`
+	// Provider is the local endpoint's wire protocol: "openai" (llama.cpp /
+	// ollama / vLLM compatible endpoints) or "anthropic". Empty means openai.
+	Provider string `env:"LLM_LOCAL_PROVIDER" default:"openai"`
+	// BaseURL is the local endpoint's base URL (e.g. http://127.0.0.1:8080/v1).
+	BaseURL string `env:"LLM_LOCAL_BASE_URL"`
+	// APIKey is the local endpoint's key; empty is normal for a local server.
+	APIKey string `env:"LLM_LOCAL_API_KEY"`
+	// Model is the local model name. Without it the rung stays off.
+	Model string `env:"LLM_LOCAL_MODEL"`
+}
+
+// Configured reports whether the local rung has enough configuration to act as a
+// chain step. Enabled alone is not enough: a missing endpoint or model must not
+// become a step that can only fail.
+func (l LocalLLMConfig) Configured() bool {
+	return l.Enabled && strings.TrimSpace(l.BaseURL) != "" && strings.TrimSpace(l.Model) != ""
+}
+
 // EmbeddingConfig holds the optional semantic embedding API settings. When
 // unset, the runtime falls back to built-in n-gram/FTS vectors.
 type EmbeddingConfig struct {
@@ -246,6 +286,15 @@ type CapacityConfig struct {
 	// reflection-based loader only supports scalars and []string), matching the
 	// MCP config pattern.
 	ToolSetsJSON string `env:"CAPACITY_TOOL_SETS"`
+	// L3Enabled turns on the model-assisted intent layer (design/14 §2.2 L3;
+	// 裁决 14.4.4, keys chosen as the landing suggestion the owner authorized).
+	// It costs one extra model call for an undecided turn, so it defaults to off:
+	// off means the layer never runs and L1/L2/L4 behave exactly as before.
+	L3Enabled bool `env:"CAPACITY_L3_ENABLED" default:"false"`
+	// L3CacheTTL is how long a model-assisted classification of the same turn text
+	// is reused (a Go duration string such as "5m"). Zero or unparsable disables
+	// reuse; empty selects the code default of 5m.
+	L3CacheTTL string `env:"CAPACITY_L3_CACHE_TTL" default:"5m"`
 }
 
 // MCPServer describes a single MCP server: a stdio subprocess (Command/Args) or

internal/config/runtimeconfig/models.go

@@ -47,6 +47,18 @@ type Group struct {
 	// last-resort fallback step then falls back to LLM_FALLBACK_MAX_TOKENS, and
 	// beyond that the adapter default applies.
 	MaxTokens int `json:"maxTokens,omitempty"`
+	// PersonaModels binds an individual persona to its own model name within this
+	// group (裁决 03.4.1: the "role" of per-role routing is the persona a turn
+	// answers as, not the LLM message role). The carrier is deliberately
+	// models.json rather than configs/personas/*.yaml, so the panel can edit the
+	// binding together with the rest of the provider configuration and no persona
+	// schema change is needed. An unknown persona id falls back to the group's
+	// default model, so a removed persona never breaks routing.
+	PersonaModels map[string]string `json:"personaModels,omitempty"`
+	// PersonaProviders binds an individual persona to another vendor's protocol
+	// (裁决 03.4.1 的 per-persona provider). Pair it with PersonaModels; an entry
+	// without a provider keeps this group's protocol.
+	PersonaProviders map[string]string `json:"personaProviders,omitempty"`
 }
 
 // ErrInvalidGroup is returned when a group fails schema validation.
@@ -75,9 +87,49 @@ func (g Group) Validate() error {
 	if g.MaxTokens < 0 {
 		return fmt.Errorf("maxTokens must be >= 0, got %d", g.MaxTokens)
 	}
+	if err := validatePersonaMap("personaModels", g.PersonaModels, false); err != nil {
+		return err
+	}
+	if err := validatePersonaMap("personaProviders", g.PersonaProviders, true); err != nil {
+		return err
+	}
 	return nil
 }
 
+// validatePersonaMap checks a persona-keyed binding map: every key must be a
+// non-empty persona id and every value a non-empty value. When providers is true
+// the values must additionally be a known protocol, so a typo in a per-persona
+// provider fails the group loudly instead of silently routing to the default.
+func validatePersonaMap(field string, m map[string]string, providers bool) error {
+	for persona, value := range m {
+		if strings.TrimSpace(persona) == "" {
+			return fmt.Errorf("%s: persona id must not be empty", field)
+		}
+		if strings.TrimSpace(value) == "" {
+			return fmt.Errorf("%s: value for persona %q must not be empty", field, persona)
+		}
+		if providers && value != ProviderOpenAI && value != ProviderAnthropic {
+			return fmt.Errorf("%s: provider %q for persona %q must be openai or anthropic", field, value, persona)
+		}
+	}
+	return nil
+}
+
+// PersonaRoute returns the per-persona model/provider binding, if one is
+// configured for persona. An empty model (or an unknown persona) is reported as
+// ok=false so the caller keeps the group's default binding.
+func (g Group) PersonaRoute(persona string) (model, provider string, ok bool) {
+	persona = strings.TrimSpace(persona)
+	if persona == "" {
+		return "", "", false
+	}
+	model = strings.TrimSpace(g.PersonaModels[persona])
+	if model == "" {
+		return "", "", false
+	}
+	return model, strings.TrimSpace(g.PersonaProviders[persona]), true
+}
+
 // ToLLMConfig maps a group to the flat LLMConfig consumed by the adapter
 // factory. The group's provider selects which config block is populated.
 func (g Group) ToLLMConfig() config.LLMConfig {
@@ -161,6 +213,14 @@ func loadFile(path string) ([]Group, error) {
 // GroupFromEnv synthesizes a single group from the active env LLM block: the
 // anthropic block when LLM_PROVIDER=anthropic, otherwise the flat OpenAI-compatible
 // block. It is the .env fallback used when models.json is absent or invalid.
+//
+// Multimodal stays false here: the flat env block has no way to declare whether
+// the main model accepts image input, and claiming a capability the endpoint may
+// not have is worse than routing the image through the vision/OCR tool (which is
+// exactly what the tool exists for). The declaration lives on the models.json
+// group's `multimodal` flag, which the provider panel writes (design/06 §0 首条;
+// 裁决 14.4.1). LLM_VISION_MODEL configures the vision *tool's* model, not the
+// main model's ability.
 func GroupFromEnv(env config.LLMConfig) []Group {
 	if env.Provider == ProviderAnthropic {
 		return []Group{{
@@ -170,7 +230,6 @@ func GroupFromEnv(env config.LLMConfig) []Group {
 			APIKey:   env.AnthropicAPIKey,
 			Model:    env.AnthropicModel,
 			Fallback: env.AnthropicFallback,
-			Multimodal: env.VisionModel != "",
 		}}
 	}
 	return []Group{{
@@ -180,7 +239,6 @@ func GroupFromEnv(env config.LLMConfig) []Group {
 		APIKey:   env.APIKey,
 		Model:    env.Model,
 		Fallback: env.Fallback,
-		Multimodal: env.VisionModel != "",
 	}}
 }
 

internal/runtime/capacity/capacity.go

@@ -110,6 +110,17 @@ type Config struct {
 	// Awakening carries the persona-level override (design §3). Zero = no
 	// override.
 	Awakening Awakening
+	// L3Enabled turns on the model-assisted intent layer (design/14 §2.2 L3;
+	// 裁决 14.4.4). It is off by default: the layer costs one model call per
+	// undecided turn, so it must be asked for explicitly. When false the
+	// classifier is never consulted, whatever L3Classifier holds.
+	L3Enabled bool
+	// L3Classifier is the model-assisted classifier the L3 layer consults when
+	// L3Enabled is true. Nil keeps the layer silent.
+	L3Classifier IntentClassifier
+	// L3CacheTTL is how long a verdict for identical turn text is reused (裁决
+	// 14.4.4 的 L3 输出缓存). Zero or negative disables reuse.
+	L3CacheTTL time.Duration
 }
 
 // Input is everything Decide needs to classify one round (design §4).
@@ -140,10 +151,13 @@ type Input struct {
 type Option func(*Decider)
 
 // Decider is the awakened-capacity decision engine. It is immutable after New
-// and safe for concurrent Decide calls.
+// and safe for concurrent Decide calls (the L3 cache is mutex-guarded).
 type Decider struct {
 	cfg Config
 	log *slog.Logger
+	// l3cache is the model-assisted intent layer's classifier + verdict cache.
+	// Nil when the layer is off, which is the default (裁决 14.4.4).
+	l3cache *l3Cache
 }
 
 // sourcedLog returns a logger tagged with the module source (project rule §10),
@@ -175,6 +189,9 @@ func New(cfg Config, opts ...Option) *Decider {
 	}
 	d := &Decider{cfg: cfg}
 	d.log = sourcedLog(nil)
+	if cfg.L3Enabled {
+		d.l3cache = newL3Cache(cfg.L3Classifier, cfg.L3CacheTTL)
+	}
 	for _, opt := range opts {
 		if opt != nil {
 			opt(d)
@@ -196,7 +213,7 @@ func (d *Decider) Decide(ctx context.Context, in Input) Decision {
 	if !d.cfg.Enabled {
 		return Decision{State: in.CurrentState, AllowedTools: append([]string(nil), in.AllToolNames...)}
 	}
-	state, conf, tool := d.intent(in)
+	state, conf, tool := d.intent(ctx, in)
 	j := judgmentFor(in, state, conf, tool)
 	state, conf = d.applyAwakening(state, conf, in)
 	allowed := d.allowedTools(state, in.AllToolNames)

internal/runtime/capacity/classifier.go

@@ -0,0 +1,129 @@
+package capacity
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"strings"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
+)
+
+// l3MaxTokens caps the classifier's reply: it is a tiny JSON object, and an
+// uncapped reply would burn budget on prose the parser then rejects.
+const l3MaxTokens = 128
+
+// l3SystemPrompt instructs the model to answer with a strict JSON judgment only.
+// It deliberately repeats "JSON only": a prose answer is an error, not a verdict.
+const l3SystemPrompt = `你是意图分类器。判断用户这一轮是在「办事」（有明确任务动作/对象），还是在「陪伴/闲聊」。
+只输出一个 JSON 对象，不要任何解释或代码块标记，格式：
+{"isTask": true|false, "taskKind": "complex"|"code"|"query"|"ops", "confidence": 0.0-1.0}
+taskKind 只在 isTask 为 true 时有意义；拿不准时把 confidence 给低（<0.6）。`
+
+// l3WireJudgment is the wire shape the classifier parses. It is separate from
+// Judgment so an unexpected field can never leak into the decision engine.
+type l3WireJudgment struct {
+	IsTask     bool    `json:"isTask"`
+	TaskKind   string  `json:"taskKind"`
+	Confidence float64 `json:"confidence"`
+}
+
+// LLMClassifier is the model-assisted intent classifier behind the L3 layer
+// (design/14 §2.2 L3; 裁决 14.4.4). It asks the adapter for a strict JSON
+// judgment and returns it; an unparsable or empty reply is an error, never a
+// guess, so the caller keeps its conservative default. It is safe for concurrent
+// use.
+type LLMClassifier struct {
+	adapter model.Adapter
+	log     *slog.Logger
+}
+
+// NewLLMClassifier builds the classifier over the runtime's LLM stack. A nil
+// adapter is allowed and makes Classify report ErrNotConfigured.
+func NewLLMClassifier(adapter model.Adapter, log *slog.Logger) *LLMClassifier {
+	if log == nil {
+		log = slog.New(slog.NewTextHandler(discard{}, nil))
+	}
+	return &LLMClassifier{adapter: adapter, log: logger.WithSource(log, "runtime/capacity")}
+}
+
+// ErrNotConfigured is returned when the classifier has no LLM stack to ask.
+var ErrNotConfigured = fmt.Errorf("capacity: L3 classifier has no model configured")
+
+// Classify asks the model for one judgment of text. It returns the raw verdict;
+// callers apply the confidence threshold (see Decider.l3).
+func (c *LLMClassifier) Classify(ctx context.Context, text string) (Judgment, error) {
+	if strings.TrimSpace(text) == "" {
+		return Judgment{}, ErrEmptyTurn
+	}
+	if c.adapter == nil {
+		return Judgment{}, ErrNotConfigured
+	}
+	resp, err := c.adapter.Chat(ctx, model.Request{
+		Messages: []model.Message{
+			model.TextMessage(model.RoleSystem, l3SystemPrompt),
+			model.TextMessage(model.RoleUser, text),
+		},
+		MaxTokens: l3MaxTokens,
+		Purpose:   "capacity-l3",
+	}, model.Options{})
+	if err != nil {
+		return Judgment{}, fmt.Errorf("capacity: L3 classify: %w", err)
+	}
+	wire, err := parseL3Judgment(resp.Content)
+	if err != nil {
+		return Judgment{}, err
+	}
+	c.log.Debug("capacity L3 verdict",
+		"is_task", wire.IsTask, "task_kind", strings.TrimSpace(wire.TaskKind),
+		"confidence", wire.Confidence)
+	return Judgment{
+		IsTask:     wire.IsTask,
+		TaskKind:   strings.TrimSpace(wire.TaskKind),
+		Confidence: clampUnit(wire.Confidence),
+	}, nil
+}
+
+// parseL3Judgment extracts the JSON object from a model reply. A reply wrapped in
+// a ```json fence is tolerated (models add one routinely), but prose around the
+// object is not: the object must be the whole answer.
+func parseL3Judgment(content string) (l3WireJudgment, error) {
+	raw := stripCodeFence(strings.TrimSpace(content))
+	if raw == "" {
+		return l3WireJudgment{}, fmt.Errorf("capacity: L3 classify: %w: empty reply", model.ErrBadRequest)
+	}
+	var wire l3WireJudgment
+	if err := json.Unmarshal([]byte(raw), &wire); err != nil {
+		return l3WireJudgment{}, fmt.Errorf("capacity: L3 classify: %w: parse reply: %v", model.ErrBadRequest, err)
+	}
+	return wire, nil
+}
+
+// stripCodeFence removes a single ```/```json fence around the payload when the
+// whole reply is fenced.
+func stripCodeFence(s string) string {
+	if !strings.HasPrefix(s, "```") {
+		return s
+	}
+	body := strings.TrimPrefix(s, "```")
+	if i := strings.IndexByte(body, '\n'); i >= 0 {
+		body = body[i+1:]
+	}
+	body = strings.TrimSuffix(body, "```")
+	return strings.TrimSpace(body)
+}
+
+// clampUnit keeps a model-reported confidence inside [0,1], so a hallucinated
+// 7.5 can never outrank the threshold arithmetic.
+func clampUnit(v float64) float64 {
+	switch {
+	case v < 0:
+		return 0
+	case v > 1:
+		return 1
+	default:
+		return v
+	}
+}

internal/runtime/capacity/l3.go

@@ -0,0 +1,134 @@
+package capacity
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"sync"
+	"time"
+)
+
+// IntentClassifier is the model-assisted intent classifier behind the L3 layer
+// (design/14 §2.2 L3; 裁决 14.4.4). It is an interface so the decision engine
+// stays testable without a model: the wiring supplies the LLM-backed
+// implementation (NewLLMClassifier), a test supplies a stub.
+//
+// Classify returns the raw judgment for one turn's text — {isTask, taskKind,
+// confidence} plus nothing else. An error means "no verdict": the caller keeps
+// the conservative default rather than guessing.
+type IntentClassifier interface {
+	Classify(ctx context.Context, text string) (Judgment, error)
+}
+
+// maxL3CacheEntries bounds the L3 verdict cache so a long-lived process cannot
+// grow it without limit. Past the bound, expired entries are dropped first and
+// the cache is cleared if every entry is still fresh.
+const maxL3CacheEntries = 256
+
+// ErrEmptyTurn is returned when the L3 classifier is asked to judge empty turn
+// text. It is a sentinel so callers (and tests) can test the category without
+// matching on the message text.
+var ErrEmptyTurn = errors.New("capacity: empty turn text for L3 classification")
+
+// DefaultL3CacheTTL is the default reuse window for an L3 verdict — the landing
+// suggestion of 裁决 14.4.4 (5m): long enough that a repeated phrase inside one
+// conversation costs one model call, short enough that a changed habit re-learns.
+const DefaultL3CacheTTL = 5 * time.Minute
+
+// l3Cache memoizes classifier verdicts per turn text for a bounded TTL, so the
+// same phrase does not cost a model call on every round. A zero TTL disables
+// reuse. The classifier call happens outside the lock: two concurrent turns must
+// not serialize on each other's model call.
+type l3Cache struct {
+	classifier IntentClassifier
+	ttl        time.Duration
+
+	mu      sync.Mutex
+	entries map[string]l3Entry
+}
+
+// l3Entry is one cached verdict with the time it was produced.
+type l3Entry struct {
+	judgment Judgment
+	at       time.Time
+}
+
+// newL3Cache builds the cache. A nil classifier yields nil, which the decider
+// treats as "L3 not available".
+func newL3Cache(classifier IntentClassifier, ttl time.Duration) *l3Cache {
+	if classifier == nil {
+		return nil
+	}
+	return &l3Cache{classifier: classifier, ttl: ttl, entries: map[string]l3Entry{}}
+}
+
+// classify returns the verdict for text, reusing a fresh cached one when
+// possible. The bool reports whether a verdict was produced; an error is returned
+// to the caller for reporting instead of being swallowed here.
+func (c *l3Cache) classify(ctx context.Context, text string) (Judgment, error) {
+	key := l3CacheKey(text)
+	if key == "" {
+		return Judgment{}, ErrEmptyTurn
+	}
+	if j, ok := c.lookup(key, time.Now()); ok {
+		return j, nil
+	}
+	j, err := c.classifier.Classify(ctx, text)
+	if err != nil {
+		return Judgment{}, err
+	}
+	c.store(key, j, time.Now())
+	return j, nil
+}
+
+// lookup returns a fresh cached verdict, if any.
+func (c *l3Cache) lookup(key string, now time.Time) (Judgment, bool) {
+	if c.ttl <= 0 {
+		return Judgment{}, false
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	e, ok := c.entries[key]
+	if !ok {
+		return Judgment{}, false
+	}
+	if now.Sub(e.at) > c.ttl {
+		return Judgment{}, false
+	}
+	return e.judgment, true
+}
+
+// store records a verdict, evicting expired entries (and, if the bound is still
+// exceeded, the whole map) so the cache cannot grow without limit.
+func (c *l3Cache) store(key string, j Judgment, now time.Time) {
+	if c.ttl <= 0 {
+		return
+	}
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if len(c.entries) >= maxL3CacheEntries {
+		c.evictExpired(now)
+	}
+	c.entries[key] = l3Entry{judgment: j, at: now}
+}
+
+// evictExpired drops entries past their TTL; when none expired, it clears the
+// map so a burst of distinct turns cannot pin the memory.
+func (c *l3Cache) evictExpired(now time.Time) {
+	dropped := 0
+	for k, e := range c.entries {
+		if now.Sub(e.at) > c.ttl {
+			delete(c.entries, k)
+			dropped++
+		}
+	}
+	if dropped == 0 {
+		c.entries = map[string]l3Entry{}
+	}
+}
+
+// l3CacheKey normalizes a turn's text into the cache key. Empty text (nothing to
+// classify) yields "".
+func l3CacheKey(text string) string {
+	return strings.TrimSpace(text)
+}

internal/runtime/capacity/l3_test.go

@@ -0,0 +1,203 @@
+package capacity
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"testing"
+	"time"
+)
+
+// stubClassifier is a deterministic IntentClassifier: it records every text it
+// was asked about so a test can pin whether L3 ran at all (裁决 14.4.4 的
+// CAPACITY_L3_ENABLED 默认关).
+type stubClassifier struct {
+	mu      sync.Mutex
+	seen    []string
+	verdict Judgment
+	err     error
+	calls   int
+}
+
+func (s *stubClassifier) Classify(_ context.Context, text string) (Judgment, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.calls++
+	s.seen = append(s.seen, text)
+	if s.err != nil {
+		return Judgment{}, s.err
+	}
+	return s.verdict, nil
+}
+
+func (s *stubClassifier) callCount() int {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.calls
+}
+
+func l3Config(c IntentClassifier, ttl time.Duration) Config {
+	cfg := activeConfig()
+	cfg.L3Enabled = true
+	cfg.L3Classifier = c
+	cfg.L3CacheTTL = ttl
+	return cfg
+}
+
+// TestDecide_L3Disabled_ClassifierNeverRuns pins the default-off red line: with
+// CAPACITY_L3_ENABLED false the classifier must never be consulted, even when one
+// is configured, so L1/L2/L4 behavior is unchanged.
+func TestDecide_L3Disabled_ClassifierNeverRuns(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, Confidence: 0.9}}
+	cfg := activeConfig()
+	cfg.L3Classifier = stub // configured but not enabled
+	cfg.L3CacheTTL = time.Minute
+
+	// A turn no heuristic can decide: L1 needs a task verb + object, L2 needs a
+	// leaning window. "那件事后来如何" carries no signal at all.
+	dec := New(cfg).Decide(context.Background(), in("那件事后来如何"))
+	if stub.callCount() != 0 {
+		t.Fatalf("classifier calls = %d, want 0 while L3 is disabled", stub.callCount())
+	}
+	if dec.State != StateQuiet {
+		t.Fatalf("state = %s, want quiet (conservative default)", dec.State)
+	}
+}
+
+// TestDecide_L3AwakensUndecidedTurn pins that an enabled L3 layer turns an
+// otherwise undecided turn into a wake with the classifier's own confidence, and
+// advertises the awake tool set.
+func TestDecide_L3AwakensUndecidedTurn(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, TaskKind: "query", Confidence: 0.82}}
+	dec := New(l3Config(stub, time.Minute)).Decide(context.Background(), in("那件事后来如何"))
+
+	if stub.callCount() != 1 {
+		t.Fatalf("classifier calls = %d, want 1", stub.callCount())
+	}
+	if dec.State != StateAwake {
+		t.Fatalf("state = %s, want awake (L3 verdict)", dec.State)
+	}
+	if dec.Confidence != 0.82 {
+		t.Fatalf("confidence = %v, want the classifier's 0.82", dec.Confidence)
+	}
+	if dec.Judgment.IsTask != true {
+		t.Errorf("judgment = %+v, want the classifier's isTask=true written back for L4", dec.Judgment)
+	}
+	if !contains(dec.AllowedTools, "web-search") {
+		t.Errorf("allowed = %v, want the awake set including web-search", dec.AllowedTools)
+	}
+}
+
+// TestDecide_L3ComplexKindWakesFull pins the quantified gate's upper branch: a
+// "complex" task kind maps to the full state rather than awake.
+func TestDecide_L3ComplexKindWakesFull(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, TaskKind: taskKindComplex, Confidence: 0.9}}
+	dec := New(l3Config(stub, time.Minute)).Decide(context.Background(), in("那件事后来如何"))
+	if dec.State != StateFull {
+		t.Fatalf("state = %s, want full for a complex task kind", dec.State)
+	}
+}
+
+// TestDecide_L3LowConfidenceIsUndecided pins the conservative gate: a verdict the
+// model is unsure about must not wake anything, and must not be written back as a
+// task either (the L4 write-back feeds the learning loop, so a hesitant verdict
+// recorded as a task would teach the wrong habit).
+func TestDecide_L3LowConfidenceIsUndecided(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, Confidence: 0.3}}
+	dec := New(l3Config(stub, time.Minute)).Decide(context.Background(), in("那件事后来如何"))
+	if stub.callCount() != 1 {
+		t.Fatalf("classifier calls = %d, want 1", stub.callCount())
+	}
+	if dec.State != StateQuiet {
+		t.Fatalf("state = %s, want quiet (below-threshold verdict is undecided)", dec.State)
+	}
+	if dec.Judgment.IsTask {
+		t.Fatalf("judgment = %+v, want isTask=false (a below-threshold verdict is not a task)", dec.Judgment)
+	}
+}
+
+// TestDecide_L3ClassifierErrorKeepsConservativeDefault pins that a model failure
+// is reported as "no verdict" rather than crashing or waking tools.
+func TestDecide_L3ClassifierErrorKeepsConservativeDefault(t *testing.T) {
+	stub := &stubClassifier{err: errors.New("upstream down")}
+	dec := New(l3Config(stub, time.Minute)).Decide(context.Background(), in("那件事后来如何"))
+	if dec.State != StateQuiet {
+		t.Fatalf("state = %s, want quiet after a classifier error", dec.State)
+	}
+}
+
+// TestDecide_L3CacheReusesVerdict pins the L3 output cache (裁决 14.4.4): the same
+// turn text costs one model call inside the TTL, and a different turn still costs
+// its own call.
+func TestDecide_L3CacheReusesVerdict(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, Confidence: 0.9}}
+	d := New(l3Config(stub, time.Minute))
+	ctx := context.Background()
+
+	for i := 0; i < 3; i++ {
+		if dec := d.Decide(ctx, in("那件事后来如何")); dec.State != StateAwake {
+			t.Fatalf("call %d state = %s, want awake", i, dec.State)
+		}
+	}
+	if got := stub.callCount(); got != 1 {
+		t.Fatalf("classifier calls = %d, want 1 (cached verdict reused)", got)
+	}
+	d.Decide(ctx, in("那件事后来如何？"))
+	if got := stub.callCount(); got != 2 {
+		t.Fatalf("classifier calls = %d, want 2 (different text is not cached)", got)
+	}
+}
+
+// TestL3Cache_ExpiredEntryIsReclassified pins the TTL bound itself.
+func TestL3Cache_ExpiredEntryIsReclassified(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, Confidence: 0.9}}
+	c := newL3Cache(stub, time.Minute)
+	ctx := context.Background()
+	if _, err := c.classify(ctx, "那件事后来如何"); err != nil {
+		t.Fatalf("classify: %v", err)
+	}
+	// Backdate the stored entry past the TTL.
+	c.mu.Lock()
+	for k, e := range c.entries {
+		e.at = time.Now().Add(-2 * time.Minute)
+		c.entries[k] = e
+	}
+	c.mu.Unlock()
+	if _, err := c.classify(ctx, "那件事后来如何"); err != nil {
+		t.Fatalf("classify: %v", err)
+	}
+	if got := stub.callCount(); got != 2 {
+		t.Fatalf("classifier calls = %d, want 2 (expired entry reclassified)", got)
+	}
+}
+
+// TestL3Cache_EmptyTextIsNotClassified pins that an empty turn is a sentinel
+// error rather than a model call.
+func TestL3Cache_EmptyTextIsNotClassified(t *testing.T) {
+	stub := &stubClassifier{verdict: Judgment{IsTask: true, Confidence: 0.9}}
+	c := newL3Cache(stub, time.Minute)
+	if _, err := c.classify(context.Background(), "   "); !errors.Is(err, ErrEmptyTurn) {
+		t.Fatalf("err = %v, want ErrEmptyTurn", err)
+	}
+	if stub.callCount() != 0 {
+		t.Fatalf("classifier calls = %d, want 0", stub.callCount())
+	}
+}
+
+// TestParseL3Judgment pins the wire parsing: a fenced JSON reply is accepted, a
+// prose reply is an error, and a hallucinated confidence is clamped.
+func TestParseL3Judgment(t *testing.T) {
+	ok, err := parseL3Judgment("```json\n{\"isTask\":true,\"taskKind\":\"query\",\"confidence\":0.7}\n```")
+	if err != nil {
+		t.Fatalf("parseL3Judgment: %v", err)
+	}
+	if !ok.IsTask || ok.TaskKind != "query" || ok.Confidence != 0.7 {
+		t.Fatalf("parsed = %+v, want isTask=true taskKind=query confidence=0.7", ok)
+	}
+	if _, err := parseL3Judgment("我觉得这是一个任务"); err == nil {
+		t.Fatal("prose reply parsed without error, want failure")
+	}
+	if got := clampUnit(7.5); got != 1 {
+		t.Errorf("clampUnit(7.5) = %v, want 1", got)
+	}
+}

internal/runtime/capacity/signals.go

@@ -1,6 +1,11 @@
+// signals.go holds the intent layer vocabulary and the L1/L2/L3 layers; the
+// package doc lives in capacity.go.
 package capacity
 
-import "strings"
+import (
+	"context"
+	"strings"
+)
 
 // defaultQuietTools is the companion-safe face (design §1): terminal + file edit
 // + memory/emotion companion. It is a function building the slice fresh so no
@@ -16,12 +21,13 @@ func defaultAwakeTools() []string {
 }
 
 // intent classifies the round. It runs L1 on the current turn, falls to L2 on
-// the recent context trend, and folds in the L4 learned-habit verdict (design §2.2)
+// the recent context trend, then to the model-assisted L3 layer when it is
-// at each layer: L4 may correct a decided result (boost / quiet→awake) or fill in
+// enabled, and folds in the L4 learned-habit verdict (design §2.2) at each layer:
-// when L1/L2 are undecided. With no matching habit L4 is silent, so a turn with no
+// L4 may correct a decided result (boost / quiet→awake) or fill in when L1/L2/L3
-// recall behaves exactly as before; otherwise the result stays conservative (低置信
+// are undecided. With no matching habit L4 is silent, so a turn with no recall
-// still rests via applyAwakening).
+// behaves exactly as before; otherwise the result stays conservative (低置信 still
-func (d *Decider) intent(in Input) (State, float64, string) {
+// rests via applyAwakening).
+func (d *Decider) intent(ctx context.Context, in Input) (State, float64, string) {
 	if len(in.Messages) == 0 {
 		return "", 0, ""
 	}
@@ -33,12 +39,44 @@ func (d *Decider) intent(in Input) (State, float64, string) {
 	if s, c, t, ok := l2(in.Messages); ok {
 		return d.mergeL4(s, c, t, l4s, l4c, l4t, l4ok)
 	}
+	if s, c, t, ok := d.l3(ctx, current); ok {
+		return d.mergeL4(s, c, t, l4s, l4c, l4t, l4ok)
+	}
 	if l4ok {
 		return l4s, l4c, l4t
 	}
 	return "", 0.3, "" // 拿不准 → conservative fallback
 }
 
+// l3 runs the model-assisted intent layer (design/14 §2.2 L3; 裁决 14.4.4): the
+// configured classifier judges the current turn and its verdict is trusted only
+// at or above the wake threshold — a low-confidence verdict is treated as
+// undecided, so a hesitant model can never wake tools on its own. A classifier
+// error is reported and treated the same way. With the layer off this returns
+// ok=false immediately, leaving L1/L2/L4 behavior byte-identical.
+func (d *Decider) l3(ctx context.Context, current string) (State, float64, string, bool) {
+	if d.l3cache == nil {
+		return "", 0, "", false
+	}
+	j, err := d.l3cache.classify(ctx, current)
+	if err != nil {
+		d.log.Warn("capacity L3 classifier unavailable, keeping the conservative default", "error", err)
+		return "", 0, "", false
+	}
+	if j.Confidence < d.cfg.MinConfidence {
+		d.log.Debug("capacity L3 verdict below threshold, treated as undecided",
+			"confidence", j.Confidence, "threshold", d.cfg.MinConfidence, "is_task", j.IsTask)
+		return "", 0, "", false
+	}
+	if !j.IsTask {
+		return StateQuiet, j.Confidence, "", true
+	}
+	if j.TaskKind == taskKindComplex {
+		return StateFull, j.Confidence, inferTool(current), true
+	}
+	return StateAwake, j.Confidence, inferTool(current), true
+}
+
 // l1 is the fast heuristic on the current turn (design §2.2 L1): a strong
 // action signal wakes (awake, or full for complex work); a clear companion
 // signal (weak + no task object) stays quiet; otherwise it is undecided and the

internal/runtime/loop/request.go

@@ -13,6 +13,10 @@ import (
 // RunStep 一致（前导指令消息、工具 schema、模型路由）。agent
 // 与推理旋钮从 ctx 解析，因此切换了角色的会话
 // 在其下一步就拿到新角色的提示词与预算（design/22 §4.2）。
+//
+// 模型路由按该 turn 的角色（persona）解析（裁决 03.4.1）。agent.buildRequest
+// （非流式路径，internal/runtime/agent/request.go）仍只按消息 role 路由——
+// 那条路径的 persona 接线不在本批次文件面内，已在回报中登记。
 func (l *Loop) buildRequest(ctx context.Context, messages []model.Message, ag *agent.Agent, knobs LoopKnobs) model.Request {
 	req := model.Request{
 		Model:           ag.Model(),
@@ -25,6 +29,15 @@ func (l *Loop) buildRequest(ctx context.Context, messages []model.Message, ag *a
 		ReasoningEffort: knobs.ReasoningEffort,
 	}
 	if ag.Router() != nil {
+		// 按 turn 的角色（persona）路由（裁决 03.4.1：per-role 的「角色」= 人格，
+		// 不是 LLM 消息 role）。路由器的 persona 感知是可选的扩展接口
+		// （model.PersonaRouter），因此只按消息 role 路由的注入方行为不变。
+		if pr, ok := ag.Router().(model.PersonaRouter); ok {
+			if m, _ := pr.RouteRequestForPersona(l.personaFor(ctx), req); m != "" {
+				req.Model = m
+			}
+			return req
+		}
 		if m, _ := ag.Router().RouteRequest(req); m != "" {
 			req.Model = m
 		}

internal/runtime/model/factory.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"strings"
 
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
 )
@@ -48,15 +49,67 @@ func NewChatChain(cfg config.LLMConfig) (*Chain, error) {
 // builds, so a provider-level reasoning decision (a thinking budget raised to fit
 // max_tokens, a reasoning_effort value downgraded or ignored) is reported with
 // its module source. A nil logger leaves the adapters' discard default in place.
+//
+// It is also the only builder that appends the optional local third rung
+// (裁决 03.4.3, primary → fallback → local), because that rung may speak a
+// different protocol than the active group and therefore needs the raw logger to
+// build its own adapter. It is appended only when the local rung is enabled AND
+// fully configured; otherwise the chain keeps its two-level shape and the reason
+// is reported.
 func NewChatChainWithLog(cfg config.LLMConfig, log *slog.Logger) (*Chain, error) {
+	var chain *Chain
+	var err error
 	switch cfg.Provider {
 	case ProviderOpenAI, "":
-		return newOpenAIChain(cfg, WithOpenAILogger(log))
+		chain, err = newOpenAIChain(cfg, WithOpenAILogger(log))
 	case ProviderAnthropic:
-		return newAnthropicChain(cfg, WithAnthropicLogger(log))
+		chain, err = newAnthropicChain(cfg, WithAnthropicLogger(log))
 	default:
 		return nil, fmt.Errorf("model: %w: provider %q", ErrUnknownProvider, cfg.Provider)
 	}
+	if err != nil {
+		return nil, err
+	}
+	if step, ok := localChainStep(cfg, log); ok {
+		chain.steps = append(chain.steps, step)
+	}
+	return chain, nil
+}
+
+// localChainStep builds the local third degradation rung as a chain step. It
+// returns ok=false (and, when the rung was asked for but is incomplete, a WARN
+// naming the missing field) when the rung is off, unconfigured or its provider is
+// unknown — a half-configured step would only ever fail, which is worse than not
+// having it.
+func localChainStep(cfg config.LLMConfig, log *slog.Logger) (Step, bool) {
+	local := cfg.Local
+	// Configured() already requires Enabled, so the rung is off by default and a
+	// disabled rung can never become a chain step. The warning is emitted only
+	// when the rung was actually asked for but is incomplete.
+	if !local.Configured() {
+		if local.Enabled {
+			warn(log, "local model rung enabled but not configured; skipping it",
+				"base_url_set", strings.TrimSpace(local.BaseURL) != "",
+				"model_set", strings.TrimSpace(local.Model) != "")
+		}
+		return Step{}, false
+	}
+	localCfg := config.LLMConfig{
+		Provider: local.Provider,
+		BaseURL:  local.BaseURL,
+		APIKey:   local.APIKey,
+		Model:    local.Model,
+	}
+	switch local.Provider {
+	case ProviderAnthropic:
+		return Step{Model: local.Model, Adapter: NewAnthropicChat(localCfg, WithAnthropicLogger(log))}, true
+	case ProviderOpenAI, "":
+		return Step{Model: local.Model, Adapter: NewOpenAIChat(localCfg, WithOpenAILogger(log))}, true
+	default:
+		warn(log, "local model rung skipped: unknown provider",
+			"provider", local.Provider, "field", "LLM_LOCAL_PROVIDER")
+		return Step{}, false
+	}
 }
 
 // newOpenAIChain builds a fallback chain from the OpenAI-compatible config block.
@@ -94,3 +147,14 @@ func DefaultModelForProvider(cfg config.LLMConfig) string {
 	}
 	return cfg.Model
 }
+
+// warn reports through the injected logger, falling back to a discard logger that
+// still carries the module source so an unsourced record can never be emitted
+// (project rule §10). It exists because a chain may be built without a logger
+// (NewChatChain) while a skipped rung must still be reported.
+func warn(log *slog.Logger, msg string, args ...any) {
+	if log == nil {
+		log = discardLogger("model")
+	}
+	log.Warn(msg, args...)
+}

internal/runtime/model/fallback.go

@@ -44,6 +44,19 @@ func (c *Chain) WithTokenBudget(groupMaxTokens, fallbackMaxTokens int) *Chain {
 	return c
 }
 
+// stepModel picks the model name for step idx of the chain. The primary step
+// prefers the request's routed model — the per-persona / per-request decision the
+// Router produced — over the group's configured model, so a routing decision is
+// never silently discarded. Every fallback step pins its own configured model, so
+// a degradation never re-sends the primary model name to a different endpoint
+// (裁决 03.4.1: per-persona 路由必须真的落到请求上).
+func stepModel(req Request, idx int, configured string) string {
+	if idx == 0 && req.Model != "" {
+		return req.Model
+	}
+	return configured
+}
+
 // applyBudget resolves the effective MaxTokens for step idx, honoring the
 // precedence: an explicit Request.MaxTokens > the group's MaxTokens > the
 // last-resort LLM_FALLBACK_MAX_TOKENS > the adapter default. The last-resort
@@ -85,8 +98,8 @@ func (c *Chain) Chat(ctx context.Context, req Request, opts Options) (Response,
 	var lastErr error
 	for i, s := range c.steps {
 		stepReq := c.applyBudget(req, i)
-		if s.Model != "" {
+		if m := stepModel(req, i, s.Model); m != "" {
-			stepReq.Model = s.Model
+			stepReq.Model = m
 		}
 		resp, err := s.Adapter.Chat(ctx, stepReq, opts)
 		if err == nil {
@@ -108,8 +121,8 @@ func (c *Chain) ChatStream(ctx context.Context, req Request, onEvent func(Stream
 	var lastErr error
 	for i, s := range c.steps {
 		stepReq := c.applyBudget(req, i)
-		if s.Model != "" {
+		if m := stepModel(req, i, s.Model); m != "" {
-			stepReq.Model = s.Model
+			stepReq.Model = m
 		}
 		delivered := false
 		wrapped := func(ev StreamEvent) {

internal/runtime/model/local_rung_test.go

@@ -0,0 +1,187 @@
+package model
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
+)
+
+// recordingServer is an OpenAI-compatible /chat/completions endpoint that records
+// the model name of every request and either fails or succeeds. It backs the
+// local-rung tests (裁决 03.4.3): the point of the rung is that a request reaches
+// the local endpoint with the local model name, and never when the rung is off.
+type recordingServer struct {
+	mu     sync.Mutex
+	models []string
+}
+
+func (s *recordingServer) modelsSeen() []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return append([]string(nil), s.models...)
+}
+
+func newRecordingServer(t *testing.T, fail bool) (*httptest.Server, *recordingServer) {
+	t.Helper()
+	rec := &recordingServer{}
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var body struct {
+			Model string `json:"model"`
+		}
+		_ = json.NewDecoder(r.Body).Decode(&body)
+		rec.mu.Lock()
+		rec.models = append(rec.models, body.Model)
+		rec.mu.Unlock()
+		if fail {
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = io.WriteString(w, `{"error":"down"}`)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = io.WriteString(w, okCompletion)
+	}))
+	t.Cleanup(srv.Close)
+	return srv, rec
+}
+
+// TestNewChatChainWithLog_LocalRungAppended verifies the third degradation level
+// (primary → fallback → local) only joins the chain when it is enabled AND fully
+// configured.
+func TestNewChatChainWithLog_LocalRungAppended(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		name  string
+		local config.LocalLLMConfig
+		want  int
+	}{
+		{"off", config.LocalLLMConfig{BaseURL: "http://127.0.0.1:1/v1", Model: "local"}, 2},
+		{"enabled but no model", config.LocalLLMConfig{Enabled: true, BaseURL: "http://127.0.0.1:1/v1"}, 2},
+		{"enabled but no base url", config.LocalLLMConfig{Enabled: true, Model: "local"}, 2},
+		{"enabled and configured", config.LocalLLMConfig{Enabled: true, BaseURL: "http://127.0.0.1:1/v1", Model: "local"}, 3},
+		{"enabled with unknown provider", config.LocalLLMConfig{Enabled: true, Provider: "gemini", BaseURL: "http://127.0.0.1:1/v1", Model: "local"}, 2},
+	}
+	for _, c := range cases {
+		c := c
+		t.Run(c.name, func(t *testing.T) {
+			t.Parallel()
+			chain, err := NewChatChainWithLog(config.LLMConfig{
+				Provider: ProviderOpenAI, BaseURL: "http://127.0.0.1:1/v1", Model: "main", Fallback: "fb",
+				Local: c.local,
+			}, nil)
+			if err != nil {
+				t.Fatalf("NewChatChainWithLog: %v", err)
+			}
+			if len(chain.steps) != c.want {
+				t.Fatalf("steps = %d, want %d", len(chain.steps), c.want)
+			}
+			if c.want == 3 && chain.steps[2].Model != "local" {
+				t.Errorf("steps[2].Model = %q, want local", chain.steps[2].Model)
+			}
+		})
+	}
+}
+
+// TestChain_Chat_LocalRungServesAfterFallback verifies the local rung really takes
+// over the request after the primary and fallback steps fail, with the local model
+// name on the wire and the local endpoint's own base URL/API key (not the group's).
+func TestChain_Chat_LocalRungServesAfterFallback(t *testing.T) {
+	t.Parallel()
+	mainSrv, _ := newRecordingServer(t, true)
+	localSrv, localRec := newRecordingServer(t, false)
+
+	chain, err := NewChatChainWithLog(config.LLMConfig{
+		Provider: ProviderOpenAI, BaseURL: mainSrv.URL, APIKey: "sk-main", Model: "main", Fallback: "fb",
+		Local: config.LocalLLMConfig{Enabled: true, BaseURL: localSrv.URL, APIKey: "sk-local", Model: "local-model"},
+	}, nil)
+	if err != nil {
+		t.Fatalf("NewChatChainWithLog: %v", err)
+	}
+	resp, err := chain.Chat(context.Background(),
+		Request{Messages: []Message{TextMessage(RoleUser, "hi")}, Purpose: "chat"}, Options{})
+	if err != nil {
+		t.Fatalf("Chain.Chat: %v", err)
+	}
+	if resp.Content != "Hello!" {
+		t.Errorf("resp.Content = %q, want Hello!", resp.Content)
+	}
+	seen := localRec.modelsSeen()
+	if len(seen) != 1 || seen[0] != "local-model" {
+		t.Fatalf("local endpoint models = %v, want [local-model]", seen)
+	}
+}
+
+// TestChain_Chat_LocalRungOffNeverCalled pins the default-off red line: with the
+// rung disabled the local endpoint must never be touched, even when every other
+// step fails.
+func TestChain_Chat_LocalRungOffNeverCalled(t *testing.T) {
+	t.Parallel()
+	mainSrv, _ := newRecordingServer(t, true)
+	localSrv, localRec := newRecordingServer(t, false)
+
+	chain, err := NewChatChainWithLog(config.LLMConfig{
+		Provider: ProviderOpenAI, BaseURL: mainSrv.URL, Model: "main", Fallback: "fb",
+		Local: config.LocalLLMConfig{BaseURL: localSrv.URL, Model: "local-model"},
+	}, nil)
+	if err != nil {
+		t.Fatalf("NewChatChainWithLog: %v", err)
+	}
+	if _, err := chain.Chat(context.Background(),
+		Request{Messages: []Message{TextMessage(RoleUser, "hi")}}, Options{}); !errors.Is(err, ErrUpstream) {
+		t.Fatalf("err = %v, want ErrUpstream", err)
+	}
+	if seen := localRec.modelsSeen(); len(seen) != 0 {
+		t.Fatalf("local endpoint called %v, want never called while the rung is off", seen)
+	}
+}
+
+// TestChain_Chat_PrimaryStepKeepsRoutedModel pins that the chain does not discard
+// the router's decision: the primary step sends the request's routed model, and
+// the fallback step still pins its own configured model (裁决 03.4.1).
+func TestChain_Chat_PrimaryStepKeepsRoutedModel(t *testing.T) {
+	t.Parallel()
+	// One endpoint serves both steps (the factory builds every step against the
+	// group's base URL): it fails for anything but the fallback model, so the
+	// recorded model names show which model each step actually sent.
+	rec := &recordingServer{}
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var body struct {
+			Model string `json:"model"`
+		}
+		_ = json.NewDecoder(r.Body).Decode(&body)
+		rec.mu.Lock()
+		rec.models = append(rec.models, body.Model)
+		rec.mu.Unlock()
+		if body.Model != "group-fb" {
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = io.WriteString(w, `{"error":"down"}`)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = io.WriteString(w, okCompletion)
+	}))
+	t.Cleanup(srv.Close)
+
+	chain, err := NewChatChainWithLog(config.LLMConfig{
+		Provider: ProviderOpenAI, BaseURL: srv.URL, Model: "group-main", Fallback: "group-fb",
+	}, nil)
+	if err != nil {
+		t.Fatalf("NewChatChainWithLog: %v", err)
+	}
+	if _, err := chain.Chat(context.Background(), Request{
+		Model:    "persona-main",
+		Messages: []Message{TextMessage(RoleUser, "hi")},
+	}, Options{}); err != nil {
+		t.Fatalf("Chain.Chat: %v", err)
+	}
+	seen := rec.modelsSeen()
+	if len(seen) != 2 || seen[0] != "persona-main" || seen[1] != "group-fb" {
+		t.Fatalf("models seen = %v, want [persona-main group-fb] (routed model first, step model on fallback)", seen)
+	}
+}

internal/runtime/model/persona_router_test.go

@@ -0,0 +1,119 @@
+package model
+
+import (
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/config/runtimeconfig"
+)
+
+// TestRouter_RouteRequestForPersona pins 裁决 03.4.1: the "role" of per-role
+// routing is the persona a turn answers as, and a persona without a binding keeps
+// the message-role behavior.
+func TestRouter_RouteRequestForPersona(t *testing.T) {
+	t.Parallel()
+	r := NewRouter("default",
+		WithRoleModel(RoleUser, "user-model"),
+		WithPersonaModel("cyrene", "persona-model"),
+		WithPersonaProvider("cyrene", ProviderAnthropic),
+		WithDefaultProvider(ProviderOpenAI),
+	)
+	req := Request{Messages: []Message{TextMessage(RoleUser, "hi")}}
+
+	if got, _ := r.RouteRequestForPersona("cyrene", req); got != "persona-model" {
+		t.Errorf("RouteRequestForPersona(cyrene) = %q, want persona-model", got)
+	}
+	if got, _ := r.RouteRequestForPersona("other", req); got != "user-model" {
+		t.Errorf("RouteRequestForPersona(other) = %q, want user-model (role fallback)", got)
+	}
+	if got, _ := r.RouteRequestForPersona("", req); got != "user-model" {
+		t.Errorf("RouteRequestForPersona(\"\") = %q, want user-model", got)
+	}
+	if got := r.RouteForPersona("cyrene"); got != "persona-model" {
+		t.Errorf("RouteForPersona(cyrene) = %q, want persona-model", got)
+	}
+	if got := r.RouteProviderForPersona("cyrene"); got != ProviderAnthropic {
+		t.Errorf("RouteProviderForPersona(cyrene) = %q, want anthropic", got)
+	}
+	if got := r.RouteProviderForPersona("other"); got != ProviderOpenAI {
+		t.Errorf("RouteProviderForPersona(other) = %q, want the default provider openai", got)
+	}
+}
+
+// TestRouter_PersonaBindingIgnoresBlankAndImageDoesNotSwitch pins two edges: a
+// blank persona/model cannot create a binding, and a persona-routed image request
+// is not silently re-routed to a vision model (that decision belongs to
+// vision.Router, 裁决 14.4.1/14.4.5).
+func TestRouter_PersonaBindingIgnoresBlankAndImageDoesNotSwitch(t *testing.T) {
+	t.Parallel()
+	r := NewRouter("default",
+		WithPersonaModel("  ", "x"),
+		WithPersonaModel("cyrene", ""),
+		WithVisionModel("vision-model"),
+	)
+	if got := r.RouteForPersona("cyrene"); got != "default" {
+		t.Errorf("RouteForPersona(cyrene) = %q, want default (no binding stored)", got)
+	}
+	img := Request{Messages: []Message{ImageMessage(RoleUser, "", "data:image/png;base64,abc")}}
+	got, needsVision := r.RouteRequestForPersona("cyrene", img)
+	if !needsVision {
+		t.Error("needsVision = false, want true for an image-bearing request")
+	}
+	if got == "vision-model" {
+		t.Errorf("RouteRequestForPersona = %q, want the persona/role model, not the vision model", got)
+	}
+}
+
+// TestRuntimeLLM_PersonaRoutesFromModelsJSON pins the carrier: a per-persona
+// binding written on the models.json group reaches the router through the hot
+// snapshot, and a reload picks up a changed binding (裁决 03.4.1 载体 = models.json)。
+func TestRuntimeLLM_PersonaRoutesFromModelsJSON(t *testing.T) {
+	path := writeRTFile(t, []runtimeconfig.Group{{
+		ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://x", Model: "group-model",
+		PersonaModels:    map[string]string{"cyrene": "persona-model"},
+		PersonaProviders: map[string]string{"cyrene": ProviderAnthropic},
+	}})
+	m := NewRuntimeLLM(path, rtEnv(), nil)
+
+	req := Request{Messages: []Message{TextMessage(RoleUser, "hi")}}
+	got, _ := m.RouteRequestForPersona("cyrene", req)
+	if got != "persona-model" {
+		t.Fatalf("RouteRequestForPersona(cyrene) = %q, want persona-model", got)
+	}
+	if got, _ := m.RouteRequestForPersona("other", req); got != "group-model" {
+		t.Fatalf("RouteRequestForPersona(other) = %q, want group-model", got)
+	}
+
+	if err := runtimeconfig.SaveModels(path, []runtimeconfig.Group{{
+		ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://x", Model: "group-model",
+	}}); err != nil {
+		t.Fatalf("SaveModels: %v", err)
+	}
+	if err := m.Reload(); err != nil {
+		t.Fatalf("Reload: %v", err)
+	}
+	if got, _ := m.RouteRequestForPersona("cyrene", req); got != "group-model" {
+		t.Fatalf("after reload RouteRequestForPersona(cyrene) = %q, want group-model (binding removed)", got)
+	}
+}
+
+// TestRuntimeLLM_NoVisionPreemptionOnImage pins that the runtime snapshot no longer
+// carries the env vision model: a configured LLM_VISION_MODEL must not switch an
+// image-bearing request to another model, because image routing is owned by
+// vision.Router (裁决 14.4.1/14.4.5).
+func TestRuntimeLLM_NoVisionPreemptionOnImage(t *testing.T) {
+	path := writeRTFile(t, []runtimeconfig.Group{{
+		ID: "openai", Provider: ProviderOpenAI, BaseURL: "https://x", Model: "group-model",
+	}})
+	env := rtEnv()
+	env.VisionModel = "vision-model"
+	m := NewRuntimeLLM(path, env, nil)
+
+	req := Request{Messages: []Message{ImageMessage(RoleUser, "", "data:image/png;base64,abc")}}
+	got, needsVision := m.RouteRequest(req)
+	if !needsVision {
+		t.Error("needsVision = false, want true for an image-bearing request")
+	}
+	if got != "group-model" {
+		t.Errorf("RouteRequest = %q, want group-model (no vision pre-emption)", got)
+	}
+}

internal/runtime/model/router.go

@@ -1,17 +1,31 @@
 package model
 
+import "strings"
+
 // Router maps roles to model names. An unknown role resolves to the configured
-// default model. When a request carries image content and a vision model is
+// default model. A Router also carries a provider per role (defaulting to the
-// configured, the request routes to the vision model. A Router also carries a
+// global provider) so a multi-vendor deployment can pair a role's model with the
-// provider per role (defaulting to the global provider) so a multi-vendor
+// correct protocol; the provider selection is surfaced via RouteProvider.
-// deployment can pair a role's model with the correct protocol; the provider
+//
-// selection is surfaced via RouteProvider.
+// Per 裁决 03.4.1 the "role" of per-role routing is the **persona** a turn
+// answers as, not the LLM message role: a persona binding wins over the
+// message-role binding, and a persona without a binding keeps the previous
+// behavior. The binding carrier is the active models.json group
+// (runtimeconfig.Group.PersonaModels / PersonaProviders).
+//
+// Image routing is deliberately NOT this router's job any more (裁决
+// 14.4.1/14.4.5): the single authority for layered image routing is
+// runtime/multimodal/vision.Router, which the loop calls with the main model's
+// real image-input capability. A "has image → switch to the vision model" rule
+// here used to bypass that decision.
 type Router struct {
 	defaultModel    string
 	byRole          map[Role]string
 	visionModel     string
 	defaultProvider string
 	providerByRole  map[Role]string
+	personaModel    map[string]string
+	personaProvider map[string]string
 }
 
 // RouterOption configures a Router.
@@ -22,11 +36,36 @@ func WithRoleModel(role Role, model string) RouterOption {
 	return func(r *Router) { r.byRole[role] = model }
 }
 
-// WithVisionModel configures the dedicated vision model.
+// WithVisionModel configures the dedicated vision model. It is kept for
+// backwards compatibility (tests and callers that route a pure image request by
+// model name) but production no longer sets it: image routing belongs to
+// vision.Router (裁决 14.4.1/14.4.5).
 func WithVisionModel(model string) RouterOption {
 	return func(r *Router) { r.visionModel = model }
 }
 
+// WithPersonaModel binds a model to a persona (裁决 03.4.1). A blank persona or
+// model is ignored so a partially configured group cannot create a binding that
+// routes a persona to an empty model.
+func WithPersonaModel(persona, model string) RouterOption {
+	return func(r *Router) {
+		if p := trimKey(persona); p != "" && model != "" {
+			r.personaModel[p] = model
+		}
+	}
+}
+
+// WithPersonaProvider binds a vendor protocol to a persona, so one persona can
+// answer through a different vendor than the group default (裁决 03.4.1). Pair it
+// with WithPersonaModel.
+func WithPersonaProvider(persona, provider string) RouterOption {
+	return func(r *Router) {
+		if p := trimKey(persona); p != "" && provider != "" {
+			r.personaProvider[p] = provider
+		}
+	}
+}
+
 // WithDefaultProvider sets the provider returned by RouteProvider for roles with
 // no explicit binding. It defaults to openai.
 func WithDefaultProvider(provider string) RouterOption {
@@ -48,6 +87,8 @@ func NewRouter(defaultModel string, opts ...RouterOption) *Router {
 		byRole:          map[Role]string{},
 		defaultProvider: ProviderOpenAI,
 		providerByRole:  map[Role]string{},
+		personaModel:    map[string]string{},
+		personaProvider: map[string]string{},
 	}
 	for _, o := range opts {
 		o(r)
@@ -55,6 +96,10 @@ func NewRouter(defaultModel string, opts ...RouterOption) *Router {
 	return r
 }
 
+// trimKey normalizes a persona id or provider name before it is stored, so
+// " cyrene" and "cyrene" cannot become two different bindings.
+func trimKey(k string) string { return strings.TrimSpace(k) }
+
 // Route returns the model for a role, falling back to the default model.
 func (r *Router) Route(role Role) string {
 	if m, ok := r.byRole[role]; ok && m != "" {
@@ -76,10 +121,15 @@ func (r *Router) RouteProvider(role Role) string {
 }
 
 // RouteRequest picks the model for a request and reports whether the request
-// needs a vision model. When the request carries image content and a vision
+// carries image content. When the request carries image content and a vision
 // model is configured, the vision model is returned with needsVision set to
 // true. Otherwise the role of the last message drives routing (user by
 // default).
+//
+// Deprecated in the production path: the loop routes by persona via
+// RouteRequestForPersona, and image routing belongs to vision.Router (裁决
+// 14.4.1/14.4.5). This method stays because it is the ModelRouter contract the
+// agent package and the existing tests are built on.
 func (r *Router) RouteRequest(req Request) (model string, needsVision bool) {
 	role := RoleUser
 	if n := len(req.Messages); n > 0 {
@@ -92,6 +142,51 @@ func (r *Router) RouteRequest(req Request) (model string, needsVision bool) {
 	return r.Route(role), needsVision
 }
 
+// PersonaRouter is the optional persona-aware routing extension of ModelRouter
+// (裁决 03.4.1). The loop detects it on the agent's router and prefers it over
+// RouteRequest, so a per-persona model/provider binding actually reaches the
+// request. It is a separate interface so a router that only knows message roles
+// keeps working unchanged.
+type PersonaRouter interface {
+	RouteRequestForPersona(personaID string, req Request) (model string, needsVision bool)
+}
+
+// RouteForPersona returns the model bound to persona, falling back to the
+// router's default model. Unlike Route (message role) this is the persona-level
+// binding: 裁决 03.4.1 defines the "role" of per-role routing as the persona.
+func (r *Router) RouteForPersona(persona string) string {
+	if m, ok := r.personaModel[trimKey(persona)]; ok && m != "" {
+		return m
+	}
+	return r.defaultModel
+}
+
+// RouteProviderForPersona returns the provider bound to persona, falling back to
+// the router's default provider (itself the active group's protocol).
+func (r *Router) RouteProviderForPersona(persona string) string {
+	if p, ok := r.personaProvider[trimKey(persona)]; ok && p != "" {
+		return p
+	}
+	return r.defaultProvider
+}
+
+// RouteRequestForPersona routes a request as the given persona: a persona
+// binding wins over the message-role decision, and a persona without a binding
+// falls back to RouteRequest so nothing changes for the unconfigured case. It
+// reports whether the request carries an image, but never switches the model to
+// the vision model — that decision belongs to vision.Router (裁决 14.4.1/14.4.5).
+func (r *Router) RouteRequestForPersona(personaID string, req Request) (model string, needsVision bool) {
+	needsVision = HasImage(req.Messages)
+	if m, ok := r.personaModel[trimKey(personaID)]; ok && m != "" {
+		return m, needsVision
+	}
+	role := RoleUser
+	if n := len(req.Messages); n > 0 {
+		role = req.Messages[n-1].Role
+	}
+	return r.Route(role), needsVision
+}
+
 // HasImage reports whether any message carries an image content part.
 func HasImage(msgs []Message) bool {
 	for _, m := range msgs {

internal/runtime/model/runtime.go

@@ -125,6 +125,17 @@ func (m *RuntimeLLM) RouteRequest(req Request) (string, bool) {
 	return r.RouteRequest(req)
 }
 
+// RouteRequestForPersona implements PersonaRouter (裁决 03.4.1): the loop routes
+// a turn as the persona it answers as, and a per-persona binding in the active
+// models.json group reaches the request through here.
+func (m *RuntimeLLM) RouteRequestForPersona(personaID string, req Request) (string, bool) {
+	r := m.load().router
+	if r == nil {
+		return "", false
+	}
+	return r.RouteRequestForPersona(personaID, req)
+}
+
 // loadInitial builds the first snapshot; a build failure leaves a nil chain so
 // calls report a clear no-model error instead of panicking.
 func (m *RuntimeLLM) loadInitial() {
@@ -160,11 +171,20 @@ func (m *RuntimeLLM) load() *runtimeChainSnapshot {
 
 // buildSnapshot turns the active group (index 0) into a chain+router. A group
 // without a base URL/model yields a nil chain (no model configured), surfaced as
-// ErrNoModel by the adapter methods. The Router keeps the env vision model so a
+// ErrNoModel by the adapter methods.
-// dedicated vision model survives a reload that only changes the vendor group.
+//
+// The env-local rung is copied onto the group's flat config because a models.json
+// group does not carry it: without that copy the third degradation level
+// (裁决 03.4.3) would silently disappear as soon as models.json exists.
+//
+// The router is seeded with the active group's per-persona bindings
+// (裁决 03.4.1). It is deliberately NOT given the env vision model: image routing
+// is owned by vision.Router, and a "has image → switch model" rule here bypassed
+// that decision (裁决 14.4.1/14.4.5).
 func buildSnapshot(groups []runtimeconfig.Group, env config.LLMConfig, log *slog.Logger) (*runtimeChainSnapshot, error) {
 	active := groups[0]
 	cfg := active.ToLLMConfig()
+	cfg.Local = env.Local
 	chain, err := NewChatChainWithLog(cfg, log)
 	if err != nil && !errors.Is(err, ErrNoModel) {
 		return nil, err
@@ -175,9 +195,20 @@ func buildSnapshot(groups []runtimeconfig.Group, env config.LLMConfig, log *slog
 		// last step of a chain that really has a fallback (design/04 §3.1).
 		chain = chain.WithTokenBudget(active.MaxTokens, env.FallbackMaxTokens)
 	}
-	router := NewRouter(DefaultModelForProvider(cfg),
+	router := NewRouter(DefaultModelForProvider(cfg), personaRouterOptions(active, cfg)...)
-		WithVisionModel(env.VisionModel),
-		WithDefaultProvider(cfg.Provider),
-	)
 	return &runtimeChainSnapshot{chain: chain, router: router, group: active, groups: groups}, nil
 }
+
+// personaRouterOptions turns the active group's per-persona model/provider
+// bindings into router options (裁决 03.4.1). It is a helper so buildSnapshot
+// stays inside the 80-line function budget.
+func personaRouterOptions(active runtimeconfig.Group, cfg config.LLMConfig) []RouterOption {
+	opts := []RouterOption{WithDefaultProvider(cfg.Provider)}
+	for persona, model := range active.PersonaModels {
+		opts = append(opts, WithPersonaModel(persona, model))
+	}
+	for persona, provider := range active.PersonaProviders {
+		opts = append(opts, WithPersonaProvider(persona, provider))
+	}
+	return opts
+}

internal/runtime/multimodal/vision/adapter.go

@@ -35,9 +35,14 @@ type OCRAdapter interface {
 // endpoint（图像作为内容部件内嵌）同时实现 VisionAdapter 与 OCRAdapter。
 // 它是开箱可用的默认实现；真实的
 // 云端 vision/OCR 提供方暴露相同协议。
+//
+// 两个方向可以跑在同一个 endpoint 的两个模型上（裁决 14.4.1 的「独立视觉
+// 模型 + OCR 模型」）：Describe 用 model（LLM_VISION_MODEL），Extract 用
+// ocrModel（LLM_OCR_MODEL），未配 OCR 模型时回落到同一个模型。
 type OpenAICompatibleAdapter struct {
 	cfg      config.LLMConfig
 	model    string
+	ocrModel string
 	client   *http.Client
 	log      *slog.Logger
 }
@@ -72,6 +77,16 @@ func WithLogger(l *slog.Logger) OpenAIOption {
 	}
 }
 
+// WithOCRModel 覆盖 OCR 方向使用的模型（默认取 cfg.OCRModel，再回落
+// 到 model）。
+func WithOCRModel(m string) OpenAIOption {
+	return func(a *OpenAICompatibleAdapter) {
+		if m != "" {
+			a.ocrModel = m
+		}
+	}
+}
+
 // NewOpenAICompatible 用 cfg 构造一个适配器，未覆盖时使用
 // cfg.Model。
 func NewOpenAICompatible(cfg config.LLMConfig, opts ...OpenAIOption) *OpenAICompatibleAdapter {
@@ -84,6 +99,13 @@ func NewOpenAICompatible(cfg config.LLMConfig, opts ...OpenAIOption) *OpenAIComp
 	for _, o := range opts {
 		o(a)
 	}
+	if a.ocrModel == "" {
+		// LLM_OCR_MODEL 未配置时 OCR 与视觉共用同一个模型（向后兼容）。
+		a.ocrModel = cfg.OCRModel
+	}
+	if a.ocrModel == "" {
+		a.ocrModel = a.model
+	}
 	return a
 }
 
@@ -92,20 +114,22 @@ func (a *OpenAICompatibleAdapter) Describe(ctx context.Context, img ImageRef, pr
 	if prompt == "" {
 		prompt = "Describe this image in detail."
 	}
-	return a.ask(ctx, img, prompt)
+	return a.ask(ctx, a.model, img, prompt)
 }
 
-// Extract 经同一 endpoint 返回图像中发现的文字。
+// Extract 经同一 endpoint 返回图像中发现的文字；当配置了独立 OCR 模型
+// （LLM_OCR_MODEL / WithOCRModel）时用它，否则与视觉模型相同。
 func (a *OpenAICompatibleAdapter) Extract(ctx context.Context, img ImageRef) (string, error) {
-	return a.ask(ctx, img, "Extract all text visible in this image. Return only the text.")
+	return a.ask(ctx, a.ocrModel, img, "Extract all text visible in this image. Return only the text.")
 }
 
-// ask 解析图像、构造 chat 请求并返回助手文本。
+// ask 解析图像、构造 chat 请求并返回助手文本。model 是本次请求使用的模型，
-func (a *OpenAICompatibleAdapter) ask(ctx context.Context, img ImageRef, prompt string) (string, error) {
+// 让两个方向能在同一 endpoint 上跑不同模型。
+func (a *OpenAICompatibleAdapter) ask(ctx context.Context, model string, img ImageRef, prompt string) (string, error) {
 	if strings.TrimSpace(a.cfg.BaseURL) == "" {
 		return "", ErrNotConfigured
 	}
-	if strings.TrimSpace(a.model) == "" {
+	if strings.TrimSpace(model) == "" {
 		return "", ErrNotConfigured
 	}
 	if err := ctx.Err(); err != nil {
@@ -115,7 +139,7 @@ func (a *OpenAICompatibleAdapter) ask(ctx context.Context, img ImageRef, prompt
 	if err != nil {
 		return "", err
 	}
-	payload, err := json.Marshal(a.request(imageURL, prompt))
+	payload, err := json.Marshal(a.request(model, imageURL, prompt))
 	if err != nil {
 		return "", fmt.Errorf("vision: %w: marshal request: %v", ErrUpstream, err)
 	}
@@ -187,9 +211,9 @@ type openAIResponseMessage struct {
 }
 
 // request 构造图像 + prompt 的线上请求体。
-func (a *OpenAICompatibleAdapter) request(imageURL, prompt string) openAIVisionRequest {
+func (a *OpenAICompatibleAdapter) request(model, imageURL, prompt string) openAIVisionRequest {
 	return openAIVisionRequest{
-		Model: a.model,
+		Model: model,
 		Messages: []openAIMessage{
 			{Role: "user", Content: []openAIPart{
 				{Type: "text", Text: prompt},

internal/runtime/multimodal/vision/ocr_model_test.go

@@ -0,0 +1,89 @@
+package vision
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
+)
+
+// modelRecorder is a /chat/completions endpoint that records the requested model,
+// so a test can pin which model each direction (Describe / Extract) asked for.
+type modelRecorder struct {
+	mu     sync.Mutex
+	models []string
+}
+
+func (r *modelRecorder) seen() []string {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	return append([]string(nil), r.models...)
+}
+
+func newModelRecorderServer(t *testing.T) (*httptest.Server, *modelRecorder) {
+	t.Helper()
+	rec := &modelRecorder{}
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var body struct {
+			Model string `json:"model"`
+		}
+		_ = json.NewDecoder(r.Body).Decode(&body)
+		rec.mu.Lock()
+		rec.models = append(rec.models, body.Model)
+		rec.mu.Unlock()
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = io.WriteString(w, `{"choices":[{"message":{"content":"ok"}}]}`)
+	}))
+	t.Cleanup(srv.Close)
+	return srv, rec
+}
+
+// TestOpenAICompatibleAdapter_OCRUsesOwnModel pins the independent OCR model
+// (裁决 14.4.1 的「独立视觉模型 + OCR 模型」): when LLM_OCR_MODEL is set the OCR
+// direction sends it, while Describe keeps the vision model.
+func TestOpenAICompatibleAdapter_OCRUsesOwnModel(t *testing.T) {
+	t.Parallel()
+	srv, rec := newModelRecorderServer(t)
+	ad := NewOpenAICompatible(config.LLMConfig{
+		BaseURL: srv.URL, Model: "vision-main", OCRModel: "ocr-special",
+	})
+
+	if _, err := ad.Describe(context.Background(), ImageRef{Source: SourceBase64, Data: "aGVsbG8="}, ""); err != nil {
+		t.Fatalf("Describe: %v", err)
+	}
+	if _, err := ad.Extract(context.Background(), ImageRef{Source: SourceBase64, Data: "aGVsbG8="}); err != nil {
+		t.Fatalf("Extract: %v", err)
+	}
+	seen := rec.seen()
+	if len(seen) != 2 || seen[0] != "vision-main" || seen[1] != "ocr-special" {
+		t.Fatalf("models seen = %v, want [vision-main ocr-special]", seen)
+	}
+}
+
+// TestOpenAICompatibleAdapter_OCRWithoutOwnModelFallsBack pins the compatibility
+// edge: without LLM_OCR_MODEL both directions use the vision model.
+func TestOpenAICompatibleAdapter_OCRWithoutOwnModelFallsBack(t *testing.T) {
+	t.Parallel()
+	srv, rec := newModelRecorderServer(t)
+	ad := NewOpenAICompatible(config.LLMConfig{BaseURL: srv.URL, Model: "vision-main"})
+
+	if _, err := ad.Extract(context.Background(), ImageRef{Source: SourceBase64, Data: "aGVsbG8="}); err != nil {
+		t.Fatalf("Extract: %v", err)
+	}
+	if seen := rec.seen(); len(seen) != 1 || seen[0] != "vision-main" {
+		t.Fatalf("models seen = %v, want [vision-main]", seen)
+	}
+	// WithOCRModel overrides cfg.OCRModel, so an explicit option still wins.
+	ad2 := NewOpenAICompatible(config.LLMConfig{BaseURL: srv.URL, Model: "vision-main", OCRModel: "cfg-ocr"}, WithOCRModel("opt-ocr"))
+	if _, err := ad2.Extract(context.Background(), ImageRef{Source: SourceBase64, Data: "aGVsbG8="}); err != nil {
+		t.Fatalf("Extract: %v", err)
+	}
+	if seen := rec.seen(); len(seen) != 2 || seen[1] != "opt-ocr" {
+		t.Fatalf("models seen = %v, want the explicit option opt-ocr", seen)
+	}
+}

internal/runtime/multimodal/vision/router.go

@@ -1,6 +1,12 @@
 package vision
 
 // Assessment 是模型对自己读图结果的置信度。
+//
+// Deprecated placeholder（裁决 14.4.1③/14.4.5②）：第二层不再是「结构化自评」，
+// 而是主模型自己按需调用视觉/OCR 工具（design/06 §0 第 2 层）。因此
+// SelfAssessment 目前没有任何生产者：主模型要复核读图效果时，直接调用
+// vision/ocr 工具即可，本包不再要求它吐出一个自评字段。保留该类型只为兼容
+// 既有调用面；新代码不要依赖它。
 type Assessment string
 
 const (
@@ -49,6 +55,11 @@ type Decision struct {
 }
 
 // RouteRequest 携带调用方在模型信息之外给出的路由提示。
+//
+// Deprecated（裁决 14.4.5②）：生产没有任何调用方填充这两个提示 —— 图像是转成
+// 文字还是留给主模型，由主模型的能力声明（models.json multimodal）与它自己
+// 按需调用视觉/OCR 工具决定，不再靠调用方猜「这张图主要是文字」。字段保留
+// 只为兼容既有测试与调用面。
 type RouteRequest struct {
 	// TextPrimary 表示用户指出图像以文字为主，因此
 	// 优先使用 OCR 工具而非通用视觉模型。

plugins/tools/io/crop.go

@@ -0,0 +1,278 @@
+package io
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"image"
+	"image/draw"
+	_ "image/gif"  // register the GIF decoder for image.Decode
+	_ "image/jpeg" // register the JPEG decoder for image.Decode
+	"image/png"
+	"log/slog"
+	"net/http"
+	"os"
+	"strings"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/pkg/plugins/sdk"
+)
+
+// Compile-time assertion that cropTool implements sdk.Tool.
+var _ sdk.Tool = (*cropTool)(nil)
+
+// Crop output limits. An upstream vision/OCR service downsamples a large image
+// before it sees it (裁决 14.4.5③), so the way to read a region in full detail is
+// to crop it and re-read the crop; these caps keep a modelled crop request from
+// turning into an unbounded allocation.
+const (
+	// maxCropSourceBytes caps the decoded source image body.
+	maxCropSourceBytes = 50 << 20
+	// maxCropPixels caps the requested region's pixel count (~16 MP).
+	maxCropPixels = 4096 * 4096
+	// cropDataURIMax is the largest crop payload the tool will return inline. A
+	// bigger crop is rejected rather than silently truncated: the model must
+	// narrow the region, not receive a half image it cannot describe.
+	cropDataURIMax = 8 << 20
+)
+
+// cropTool crops an axis-aligned region out of an image and returns it as a
+// base64 data URI, so the agent can re-read a zoomed region of a large image with
+// the vision or OCR tool (裁决 14.4.5③：「图片按区域裁切」，供模型自行裁大图分区
+// 精读). Path inputs go through the file tool's sandbox — this tool never widens
+// file access; URL inputs use the shared SSRF-guarded client.
+type cropTool struct {
+	file         *fileTool
+	client       *http.Client
+	allowedHosts []string
+	log          *slog.Logger
+}
+
+func newCropTool(t *tools, file *fileTool) *cropTool {
+	return &cropTool{
+		file:         file,
+		client:       t.client,
+		allowedHosts: t.allowedHosts,
+		log:          t.log,
+	}
+}
+
+// Name implements sdk.Tool.
+func (c *cropTool) Name() string { return "image-crop" }
+
+// Description implements sdk.Tool. It names the downsampling reason, because the
+// model decides whether to crop from this text alone.
+func (c *cropTool) Description() string {
+	return "Crop a rectangular region out of an image and return the crop (PNG data URI) plus its size. " +
+		"Use it to read a large image in parts: an image service downsamples big images, so cropping a region " +
+		"and re-reading the crop recovers the detail. Coordinates are 0-based pixels from the top-left."
+}
+
+// Parameters implements sdk.Tool.
+func (c *cropTool) Parameters() (map[string]any, error) {
+	return map[string]any{
+		"type": "object",
+		"properties": map[string]any{
+			"image":  map[string]any{"type": "string", "description": "The image: a local path, an http(s) URL, or a base64/data: URI."},
+			"x":      map[string]any{"type": "integer", "description": "Left edge of the region, in pixels (0-based)."},
+			"y":      map[string]any{"type": "integer", "description": "Top edge of the region, in pixels (0-based)."},
+			"width":  map[string]any{"type": "integer", "description": "Region width in pixels."},
+			"height": map[string]any{"type": "integer", "description": "Region height in pixels."},
+		},
+		"required": []any{"image", "x", "y", "width", "height"},
+	}, nil
+}
+
+// Execute implements sdk.Tool.
+func (c *cropTool) Execute(ctx context.Context, args any) (any, error) {
+	m, ok := args.(map[string]any)
+	if !ok {
+		return nil, fmt.Errorf("io: image-crop: args must be an object")
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	src := argString(m, "image")
+	if strings.TrimSpace(src) == "" {
+		return nil, fmt.Errorf("io: image-crop: image is required")
+	}
+	region, err := cropRegion(m)
+	if err != nil {
+		return nil, err
+	}
+	data, err := c.load(ctx, src)
+	if err != nil {
+		return nil, err
+	}
+	img, _, err := image.Decode(bytes.NewReader(data))
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: decode image: %w", err)
+	}
+	bounds := img.Bounds()
+	if err := checkRegion(region, bounds); err != nil {
+		return nil, err
+	}
+	cropped := cropToRGBA(img, region)
+	payload, err := encodePNG(cropped)
+	if err != nil {
+		return nil, err
+	}
+	c.log.Debug("io image-crop: cropped region",
+		"source_width", bounds.Dx(), "source_height", bounds.Dy(),
+		"x", region.Min.X, "y", region.Min.Y,
+		"width", region.Dx(), "height", region.Dy(), "bytes", len(payload))
+	return map[string]any{
+		"image":  "data:image/png;base64," + base64.StdEncoding.EncodeToString(payload),
+		"format": "image/png",
+		"width":  region.Dx(),
+		"height": region.Dy(),
+		"region": map[string]any{"x": region.Min.X, "y": region.Min.Y, "width": region.Dx(), "height": region.Dy()},
+		"source": map[string]any{"width": bounds.Dx(), "height": bounds.Dy()},
+	}, nil
+}
+
+// cropRegion reads and validates the region arguments. A non-positive width or
+// height, or a negative offset, is rejected (never clamped: a clamped crop would
+// silently hand the model a different region than it asked for).
+func cropRegion(m map[string]any) (image.Rectangle, error) {
+	x, ok := argInt(m, "x")
+	if !ok {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: x must be an integer")
+	}
+	y, ok := argInt(m, "y")
+	if !ok {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: y must be an integer")
+	}
+	w, ok := argInt(m, "width")
+	if !ok {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: width must be an integer")
+	}
+	h, ok := argInt(m, "height")
+	if !ok {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: height must be an integer")
+	}
+	if x < 0 || y < 0 {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: x and y must be >= 0, got (%d,%d)", x, y)
+	}
+	if w <= 0 || h <= 0 {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: width and height must be > 0, got (%d,%d)", w, h)
+	}
+	if int64(w)*int64(h) > maxCropPixels {
+		return image.Rectangle{}, fmt.Errorf("io: image-crop: region of %dx%d exceeds the %d-pixel limit", w, h, maxCropPixels)
+	}
+	return image.Rect(x, y, x+w, y+h), nil
+}
+
+// checkRegion rejects a region that is not fully inside the image.
+func checkRegion(r image.Rectangle, bounds image.Rectangle) error {
+	if !r.In(bounds) {
+		return fmt.Errorf("io: image-crop: region %v is outside the image %v", r, bounds)
+	}
+	return nil
+}
+
+// cropToRGBA copies the region into a fresh RGBA image so the result does not
+// alias the (possibly huge) source and always re-encodes losslessly.
+func cropToRGBA(img image.Image, r image.Rectangle) *image.RGBA {
+	dst := image.NewRGBA(image.Rect(0, 0, r.Dx(), r.Dy()))
+	draw.Draw(dst, dst.Bounds(), img, r.Min, draw.Src)
+	return dst
+}
+
+// encodePNG encodes the crop, refusing a payload above the inline cap so a huge
+// crop is reported instead of flooding the tool result.
+func encodePNG(img image.Image) ([]byte, error) {
+	var buf bytes.Buffer
+	if err := png.Encode(&buf, img); err != nil {
+		return nil, fmt.Errorf("io: image-crop: encode crop: %w", err)
+	}
+	if buf.Len() > cropDataURIMax {
+		return nil, fmt.Errorf("io: image-crop: crop is %d bytes, above the %d-byte inline limit; crop a smaller region", buf.Len(), cropDataURIMax)
+	}
+	return buf.Bytes(), nil
+}
+
+// load reads the source image: a local path through the file sandbox, an http(s)
+// URL through the shared SSRF-guarded client, or a base64/data: URI payload.
+func (c *cropTool) load(ctx context.Context, src string) ([]byte, error) {
+	switch {
+	case strings.HasPrefix(src, "data:"):
+		return decodeCropDataURI(src)
+	case strings.HasPrefix(src, "http://"), strings.HasPrefix(src, "https://"):
+		return c.fetch(ctx, src)
+	default:
+		return c.readFile(src)
+	}
+}
+
+// decodeCropDataURI decodes a "data:<mime>;base64,<payload>" source.
+func decodeCropDataURI(src string) ([]byte, error) {
+	comma := strings.IndexByte(src, ',')
+	if comma < 0 || !strings.Contains(src[:comma], ";base64") {
+		return nil, fmt.Errorf("io: image-crop: unsupported data URI (expected base64)")
+	}
+	data, err := base64.StdEncoding.DecodeString(src[comma+1:])
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: decode data URI: %w", err)
+	}
+	if len(data) > maxCropSourceBytes {
+		return nil, fmt.Errorf("io: image-crop: source exceeds the %d-byte limit", maxCropSourceBytes)
+	}
+	return data, nil
+}
+
+// readFile reads a path through the file tool's sandbox so cropping can never
+// reach a file the file tool could not read (裁决 13.4.4：文件沙箱唯一实现处).
+func (c *cropTool) readFile(p string) ([]byte, error) {
+	if c.file == nil {
+		return nil, fmt.Errorf("io: image-crop: no sandbox configured")
+	}
+	real, err := c.file.resolveExisting(p)
+	if err != nil {
+		return nil, err
+	}
+	fh, err := os.Open(real)
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: open: %w", err)
+	}
+	defer fh.Close()
+	data, truncated, err := readLimited(fh, maxCropSourceBytes)
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: read: %w", err)
+	}
+	if truncated {
+		return nil, fmt.Errorf("io: image-crop: source exceeds the %d-byte limit", maxCropSourceBytes)
+	}
+	return data, nil
+}
+
+// fetch downloads an http(s) source through the shared client, applying the same
+// SSRF guard as the other network tools.
+func (c *cropTool) fetch(ctx context.Context, rawURL string) ([]byte, error) {
+	if c.client == nil {
+		return nil, fmt.Errorf("io: image-crop: no http client configured")
+	}
+	if _, err := validateRequestURL(ctx, rawURL, c.allowedHosts); err != nil {
+		return nil, err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, rawURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: build request: %w", err)
+	}
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: fetch: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("io: image-crop: fetch: status %d", resp.StatusCode)
+	}
+	data, truncated, err := readLimited(resp.Body, maxCropSourceBytes)
+	if err != nil {
+		return nil, fmt.Errorf("io: image-crop: read response: %w", err)
+	}
+	if truncated {
+		return nil, fmt.Errorf("io: image-crop: source exceeds the %d-byte limit", maxCropSourceBytes)
+	}
+	return data, nil
+}

plugins/tools/io/crop_test.go

@@ -0,0 +1,205 @@
+package io
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"image"
+	"image/color"
+	"image/png"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
+	"git.yeij.top/AskaEth/Cyrene_v2/pkg/plugins/sdk"
+)
+
+// gradientPNG writes an image whose pixel (x,y) encodes its own coordinates in the
+// red/green channels. That makes a crop self-verifying: if the crop's top-left
+// pixel is not RGBA{sourceX, sourceY, 0, 255} the wrong region was returned.
+func gradientPNG(t *testing.T, w, h int) []byte {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, w, h))
+	for y := 0; y < h; y++ {
+		for x := 0; x < w; x++ {
+			img.Set(x, y, color.RGBA{R: uint8(x), G: uint8(y), A: 255})
+		}
+	}
+	var buf bytes.Buffer
+	if err := png.Encode(&buf, img); err != nil {
+		t.Fatalf("png.Encode: %v", err)
+	}
+	return buf.Bytes()
+}
+
+// decodeCropResult pulls the PNG out of a crop tool result and decodes it.
+func decodeCropResult(t *testing.T, result any) image.Image {
+	t.Helper()
+	m, ok := result.(map[string]any)
+	if !ok {
+		t.Fatalf("result type = %T, want map[string]any", result)
+	}
+	uri, _ := m["image"].(string)
+	if !strings.HasPrefix(uri, "data:image/png;base64,") {
+		t.Fatalf("image field = %q, want a PNG data URI", uri)
+	}
+	raw, err := base64.StdEncoding.DecodeString(strings.TrimPrefix(uri, "data:image/png;base64,"))
+	if err != nil {
+		t.Fatalf("decode data URI: %v", err)
+	}
+	img, _, err := image.Decode(bytes.NewReader(raw))
+	if err != nil {
+		t.Fatalf("decode crop: %v", err)
+	}
+	return img
+}
+
+func newCropToolForTest(t *testing.T, extra ...Option) (*cropTool, string) {
+	t.Helper()
+	dir := t.TempDir()
+	set := buildTools(t, &config.Config{DataDir: dir}, extra...)
+	tool, ok := findTool(t, set, "image-crop").(*cropTool)
+	if !ok {
+		t.Fatalf("image-crop tool has type %T, want *cropTool", findTool(t, set, "image-crop"))
+	}
+	return tool, dir
+}
+
+// TestCropTool_CropsRequestedRegion pins the region arithmetic: the returned crop
+// must be exactly the requested region with the requested pixels, not merely the
+// right size (裁决 14.4.5③).
+func TestCropTool_CropsRequestedRegion(t *testing.T) {
+	t.Parallel()
+	tool, dir := newCropToolForTest(t)
+	path := filepath.Join(dir, "src.png")
+	if err := os.WriteFile(path, gradientPNG(t, 100, 80), filePerm); err != nil {
+		t.Fatalf("write source: %v", err)
+	}
+
+	res, err := tool.Execute(context.Background(), map[string]any{
+		"image": path, "x": 10, "y": 20, "width": 30, "height": 40,
+	})
+	if err != nil {
+		t.Fatalf("Execute: %v", err)
+	}
+	img := decodeCropResult(t, res)
+	if img.Bounds().Dx() != 30 || img.Bounds().Dy() != 40 {
+		t.Fatalf("crop size = %dx%d, want 30x40", img.Bounds().Dx(), img.Bounds().Dy())
+	}
+	got := color.NRGBAModel.Convert(img.At(0, 0)).(color.NRGBA)
+	if got.R != 10 || got.G != 20 {
+		t.Fatalf("top-left pixel = %v, want the source pixel (10,20)", got)
+	}
+	last := color.NRGBAModel.Convert(img.At(29, 39)).(color.NRGBA)
+	if last.R != 39 || last.G != 59 {
+		t.Fatalf("bottom-right pixel = %v, want the source pixel (39,59)", last)
+	}
+}
+
+// TestCropTool_RejectsRegionOutsideImage pins fail-loud instead of clamping: a
+// clamp would hand the model a different region than it asked for.
+func TestCropTool_RejectsRegionOutsideImage(t *testing.T) {
+	t.Parallel()
+	tool, dir := newCropToolForTest(t)
+	path := filepath.Join(dir, "src.png")
+	if err := os.WriteFile(path, gradientPNG(t, 50, 50), filePerm); err != nil {
+		t.Fatalf("write source: %v", err)
+	}
+	cases := []map[string]any{
+		{"image": path, "x": 40, "y": 0, "width": 20, "height": 10},
+		{"image": path, "x": 0, "y": 40, "width": 10, "height": 20},
+		{"image": path, "x": -1, "y": 0, "width": 10, "height": 10},
+		{"image": path, "x": 0, "y": 0, "width": 0, "height": 10},
+		{"image": path, "x": 0, "y": 0, "width": 10, "height": -5},
+	}
+	for _, args := range cases {
+		if _, err := tool.Execute(context.Background(), args); err == nil {
+			t.Errorf("args %v accepted, want an out-of-bounds error", args)
+		}
+	}
+}
+
+// TestCropTool_RejectsPathOutsideSandbox pins the file sandbox reuse: cropping can
+// never reach a file the file tool could not read.
+func TestCropTool_RejectsPathOutsideSandbox(t *testing.T) {
+	t.Parallel()
+	tool, _ := newCropToolForTest(t)
+	outside := filepath.Join(t.TempDir(), "outside.png")
+	if err := os.WriteFile(outside, gradientPNG(t, 10, 10), filePerm); err != nil {
+		t.Fatalf("write outside image: %v", err)
+	}
+	if _, err := tool.Execute(context.Background(), map[string]any{
+		"image": outside, "x": 0, "y": 0, "width": 2, "height": 2,
+	}); err == nil {
+		t.Fatal("path outside the data dir accepted, want a sandbox rejection")
+	}
+}
+
+// TestCropTool_AcceptsDataURIAndURL pins the other two sources: a data: URI and an
+// http(s) URL both decode into a crop.
+func TestCropTool_AcceptsDataURIAndURL(t *testing.T) {
+	t.Parallel()
+	src := gradientPNG(t, 20, 20)
+	uri := "data:image/png;base64," + base64.StdEncoding.EncodeToString(src)
+
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "image/png")
+		_, _ = w.Write(src)
+	}))
+	t.Cleanup(srv.Close)
+
+	tool, _ := newCropToolForTest(t, WithAllowedHosts(serverHost(srv)))
+	cases := []string{uri, srv.URL + "/img.png"}
+	for _, source := range cases {
+		res, err := tool.Execute(context.Background(), map[string]any{
+			"image": source, "x": 5, "y": 5, "width": 4, "height": 3,
+		})
+		if err != nil {
+			t.Fatalf("Execute(%s): %v", source, err)
+		}
+		if img := decodeCropResult(t, res); img.Bounds().Dx() != 4 || img.Bounds().Dy() != 3 {
+			t.Fatalf("source %s crop size = %dx%d, want 4x3", source, img.Bounds().Dx(), img.Bounds().Dy())
+		}
+	}
+}
+
+// TestCropTool_RejectsUnsupportedDataURI pins a non-base64 data URI as an error
+// rather than a silent empty decode.
+func TestCropTool_RejectsUnsupportedDataURI(t *testing.T) {
+	t.Parallel()
+	tool, _ := newCropToolForTest(t)
+	if _, err := tool.Execute(context.Background(), map[string]any{
+		"image": "data:image/png,plaintext", "x": 0, "y": 0, "width": 1, "height": 1,
+	}); err == nil {
+		t.Fatal("non-base64 data URI accepted, want an error")
+	}
+}
+
+// TestCropTool_RegisteredInSet pins that the tool ships with the default set and
+// advertises a usable schema (the agent only sees it if it is registered).
+func TestCropTool_RegisteredInSet(t *testing.T) {
+	t.Parallel()
+	tool, _ := newCropToolForTest(t)
+	if tool.Name() != "image-crop" {
+		t.Errorf("Name = %q, want image-crop", tool.Name())
+	}
+	params, err := tool.Parameters()
+	if err != nil {
+		t.Fatalf("Parameters: %v", err)
+	}
+	if params["type"] != "object" {
+		t.Errorf("schema type = %v, want object", params["type"])
+	}
+	var _ sdk.Tool = tool
+	// A nil/mis-typed argument set must be an error, not a panic.
+	if _, err := tool.Execute(context.Background(), "not-a-map"); err == nil {
+		t.Error("non-object args accepted, want an error")
+	}
+	if _, err := tool.Execute(context.Background(), map[string]any{}); err == nil {
+		t.Error("missing image accepted, want an error")
+	}
+}

plugins/tools/io/doc.go

@@ -1,7 +1,7 @@
 // Package io implements the built-in I/O and network tools for Cyrene v2
-// (DevDocs/design/09-插件生态.md). It exposes file, http, web-search, web-fetch
+// (DevDocs/design/09-插件生态.md). It exposes file, image-crop, http, web-search,
-// and knowledge as pkg/plugins/sdk.Tool values, wired to the process-internal
+// web-fetch and knowledge as pkg/plugins/sdk.Tool values, wired to the
-// config, logger and runtime/memory retriever.
+// process-internal config, logger and runtime/memory retriever.
 //
 // Build the full configured tool set with New(cfg, opts...). Tools() and
 // Register(reg) are convenience wrappers that use platform defaults; production
@@ -13,6 +13,10 @@
 //   - file: every path is cleaned and validated to stay inside the configured
 //     data directory or an explicit whitelist; ".." traversal and symlink escape
 //     are rejected; reads and writes are size-capped.
+//   - image-crop: crops a region out of a large image so the agent can read it in
+//     parts (an image service downsamples big images); path sources go through the
+//     file sandbox, URL sources through the SSRF guard, and the returned data URI
+//     is size-capped.
 //   - http: GET/POST only, timeouts, response truncation and SSRF protection
 //     (loopback/private/link-local addresses and localhost are refused unless
 //     the host is on an explicit allowlist).

plugins/tools/io/tools.go

@@ -202,8 +202,10 @@ func Register(reg sdk.Registrar) error {
 
 // build assembles the tools sharing this set's client, limits and logger.
 func (t *tools) build() []sdk.Tool {
+	file := newFileTool(t)
 	return []sdk.Tool{
-		newFileTool(t),
+		file,
+		newCropTool(t, file),
 		newHTTPTool(t),
 		newWebSearchTool(t),
 		newWebFetchTool(t),

plugins/tools/io/tools_test.go

@@ -9,16 +9,16 @@ import (
 	"git.yeij.top/AskaEth/Cyrene_v2/pkg/plugins/sdk"
 )
 
-func TestTools_ReturnsAllFiveTools(t *testing.T) {
+func TestTools_ReturnsEveryTool(t *testing.T) {
 	t.Parallel()
 	set, err := New(&config.Config{DataDir: t.TempDir()})
 	if err != nil {
 		t.Fatalf("New: %v", err)
 	}
-	if len(set) != 5 {
+	if len(set) != 6 {
-		t.Fatalf("expected 5 tools, got %d", len(set))
+		t.Fatalf("expected 6 tools, got %d", len(set))
 	}
-	want := []string{"file", "http", "web-search", "web-fetch", "knowledge"}
+	want := []string{"file", "image-crop", "http", "web-search", "web-fetch", "knowledge"}
 	seen := map[string]bool{}
 	for _, tool := range set {
 		seen[tool.Name()] = true
@@ -53,7 +53,7 @@ func TestRegister_RegistersEveryTool(t *testing.T) {
 	if err := Register(reg); err != nil {
 		t.Fatalf("Register: %v", err)
 	}
-	for _, name := range []string{"file", "http", "web-search", "web-fetch", "knowledge"} {
+	for _, name := range []string{"file", "image-crop", "http", "web-search", "web-fetch", "knowledge"} {
 		c, err := reg.Get(name)
 		if err != nil {
 			t.Fatalf("Get(%q): %v", name, err)