feat(persona,model,loop): 人格 thinking 配置 + 5 个死字段接线 + 推理旋钮（按 provider 映射）

按 DevDocs/design/01 §2.1/§2.2 与 design/04 §3.2 实现（规格含联网核过的官方依据：思考内容刻意不角色化、不写分步思考指令、思考控制只走参数级）。
- 人格 schema 新增 thinking：budgetTokens / effort / showToUser(*bool，省略=nil=保持现行为，显式 false=只落库) / mode(default|on|off→Enable 三态)；非法 mode/负预算 → ErrInvalidThinking（不静默）
- 5 个死字段接上注入：personality→values→speechStyle→catchphrase→background 拼为独立段落（带【】小标题，空值不拼）；**全空时输出与旧实现逐字节一致**（有专门测试）
- model.Request 新增 Thinking{ BudgetTokens, Enable } 与 ReasoningEffort；新增 model/reasoning.go：厂商识别（模型名→baseURL 兜底）、取值白名单（OpenAI 系 none…max / DeepSeek low|high|max）、非法值降级+WARN、**不支持一律 WARN 而非静默**；Anthropic 映射 thinking{budget_tokens} 并**保证 budget<max_tokens**（不足时抬高 max_tokens+WARN，正是历史上思考吃光预算→空回复那个坑）
- loop：新增 Options.ThinkingShowToUser(*bool) 仅门控 thinking_* 帧（正文/工具帧不受影响）；场景级 mute 语义不变
- 补一处任务清单外但必需的接线：persona→model.Request 的 thinking 映射（否则 budget/effort/mode 会变成新的死字段）；showToUser 刻意不产生 Thinking（纯呈现开关）
- 管理端：personaUpsertRequest 补 thinking DTO + 校验（400）；PUT 省略时**保留已存块**（防旧客户端抹配置）；写侧 yaml round-trip 已验证
- Docs/api-client v0.40→v0.41（可选请求字段）
- 测试：26 个新用例（loader 解析/拼接逐字节/映射、anthropic 非流式+流式预算约束、openai 透传/降级/丢弃、Qwen 诚实 WARN、loop 门控、DTO round-trip）；3 次变异验证（省略与 false 混同 / 去掉预算约束 / 短路门控 各自 FAIL）
- 验收：go build/vet/test 全绿（含 57 包）+ linux/darwin 交叉编译 + 前端 build；唯一 FAIL 是既有 flake TestInterruptCancelsTurnAndClearsPending（3/20 新代码 vs 3/20 纯 HEAD，已归因非本次引入）

internal/persona/loader/persona.go

@@ -5,6 +5,9 @@
 package loader
 
 import (
+	"errors"
+	"fmt"
+
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/persona/emotion"
 )
 
@@ -17,6 +20,22 @@ const (
 	defaultAffectionDelta = 5
 )
 
+// Thinking-move values accepted by ThinkingParams.Mode (design/01 §2.1). The
+// empty string is equivalent to ThinkingModeDefault.
+const (
+	// ThinkingModeDefault leaves the provider's own reasoning behavior alone.
+	ThinkingModeDefault = "default"
+	// ThinkingModeOn explicitly enables reasoning where the provider has a switch.
+	ThinkingModeOn = "on"
+	// ThinkingModeOff explicitly disables reasoning where the provider has a switch.
+	ThinkingModeOff = "off"
+)
+
+// ErrInvalidThinking is wrapped by the thinking-config validation error so a
+// caller can detect a bad `thinking` block (unknown mode, negative budget)
+// instead of seeing it silently ignored.
+var ErrInvalidThinking = errors.New("persona: invalid thinking config")
+
 // defaultMemoryNS is the namespace prefix used when a persona omits a concrete
 // memory namespace; the full namespace becomes prefix + "." + persona id.
 const defaultMemoryNS = "persona"
@@ -50,6 +69,45 @@ type AffectionParams struct {
 	Delta   int `yaml:"delta"`
 }
 
+// ThinkingParams is the persona's optional `thinking` section (design/01 §2.1).
+// It describes presentation/resource knobs only — never an ability bound — and
+// defaults are chosen so an absent section changes nothing. It is marshaled by
+// the admin persona write path, so every field is omitempty: a persona that
+// configures no thinking gets no `thinking:` key in its YAML.
+type ThinkingParams struct {
+	// BudgetTokens is the reasoning budget (Anthropic thinking.budget_tokens; the
+	// official semantic is a target, not a hard cap). Zero = unset.
+	BudgetTokens int `yaml:"budgetTokens,omitempty"`
+	// Effort is the OpenAI-compatible reasoning strength (reasoning_effort). The
+	// accepted values depend on the provider; the model layer validates them
+	// against its per-provider whitelist (design/04 §3.2).
+	Effort string `yaml:"effort,omitempty"`
+	// ShowToUser says whether streamed thinking frames are pushed to the client.
+	// It is a POINTER on purpose: a missing key means "keep the current behavior"
+	// (thinking frames are shown), while an explicit false means "store it, but
+	// do not push it". A plain bool would conflate "unset" with "off".
+	ShowToUser *bool `yaml:"showToUser,omitempty"`
+	// Mode is the explicit hard switch: default | on | off. Empty = default.
+	Mode string `yaml:"mode,omitempty"`
+}
+
+// Enable maps Mode onto the model layer's tri-state switch: "on" → true, "off" →
+// false, ""/"default" → nil (no explicit switch, leave it to the provider). The
+// reasoning knobs the model layer consumes never include a null switch, so
+// "default" cannot accidentally turn provider thinking on.
+func (t ThinkingParams) Enable() *bool {
+	switch t.Mode {
+	case ThinkingModeOn:
+		v := true
+		return &v
+	case ThinkingModeOff:
+		v := false
+		return &v
+	default:
+		return nil
+	}
+}
+
 // Persona is a loaded persona definition. It describes who a character is (the
 // identity, personality, speech style, catchphrase, background, values) and
 // never restricts what that character can do.
@@ -85,7 +143,10 @@ type Persona struct {
 	Values       []string        `yaml:"values"`
 	Emotion      EmotionParams   `yaml:"emotion"`
 	Affection    AffectionParams `yaml:"affection"`
-	Visual       PersonaVisual   `yaml:"visual,omitempty"`
+	// Thinking is the optional reasoning/presentation config (design/01 §2.1);
+	// omitted when the persona configures none, so no existing YAML gains noise.
+	Thinking ThinkingParams `yaml:"thinking,omitempty"`
+	Visual   PersonaVisual  `yaml:"visual,omitempty"`
 	// TriggerWords are the role-name words that, when a public-platform group
 	// message mentions one, route the message into the participation PROBING
 	// stage even without a direct @ (design/18 §2 触发②). Each persona defines its
@@ -143,3 +204,19 @@ func (p *Persona) AffectionStep() int {
 	}
 	return defaultAffectionDelta
 }
+
+// ValidateThinking checks the optional `thinking` section and returns a
+// %w-wrapped ErrInvalidThinking error for an unrecognized mode or a negative
+// budget, so a bad value is reported instead of silently ignored.
+func (p *Persona) ValidateThinking() error {
+	switch p.Thinking.Mode {
+	case "", ThinkingModeDefault, ThinkingModeOn, ThinkingModeOff:
+	default:
+		return fmt.Errorf("%w: mode %q (want %s|%s|%s)",
+			ErrInvalidThinking, p.Thinking.Mode, ThinkingModeDefault, ThinkingModeOn, ThinkingModeOff)
+	}
+	if p.Thinking.BudgetTokens < 0 {
+		return fmt.Errorf("%w: budgetTokens %d must not be negative", ErrInvalidThinking, p.Thinking.BudgetTokens)
+	}
+	return nil
+}