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）

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
-// dedicated vision model survives a reload that only changes the vendor group.
+// ErrNoModel by the adapter methods.
+//
+// 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),
-		WithVisionModel(env.VisionModel),
-		WithDefaultProvider(cfg.Provider),
-	)
+	router := NewRouter(DefaultModelForProvider(cfg), personaRouterOptions(active, cfg)...)
 	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
+}