feat(persona,web): 人格读侧（thinking 三态 + 角色级 mood）+ 面板表单 + mood 播种

按 design/04 §3.2（thinking 语义，showToUser 三态）+ design/01 §2.1 + 主人两条定论（心情跟角色不跟会话；mood 初值走口径 ①：由角色读端点暴露、前端加载播种）。
- 管理侧 GET /admin/personas 的 PersonaSummary 增 thinking（budgetTokens/effort/mode/showToUser）——**showToUser 保持三态**（未配置 ≠ false）
- 用户侧 GET /personas 增**角色级 mood**（取自 emotion 层该角色当前状态，非从消息推断）→ 前端加载播种 currentMood，消除「刷新后心情徽标短暂为空」
- 前端 Personas 页加 thinking 四控件（预算/effort/模式/showToUser 三态）：只做输入校验，**provider 是否真支持由后端 WARN 决定，前端不假装能力**
- 先拆 useAppStore 选择器（原 494/500）到独立模块再做，避免越线
- Docs/api-client 版本号 +1（两处契约 + 三态与角色级 mood 语义）
- 验收：go build/vet/test 全绿 + linux/darwin 交叉编译 + 前端 build 绿 + personaSession/messageSync 逻辑测试通过

frontend/web/src/components/Nav.tsx

@@ -3,7 +3,8 @@ import { applyTheme, readTheme, type ThemeMode } from "../lib/theme";
 import { getAuthToken } from "../lib/api";
 import { labelFor } from "../lib/enums";
 import { personaAvatar } from "../lib/persona";
-import { useAppStore, useCurrentMood, useCurrentPersona } from "../store/useAppStore";
+import { useAppStore } from "../store/useAppStore";
+import { useCurrentMood, useCurrentPersona } from "../store/personaSelectors";
 import { Icon } from "./Icon";
 import { NavItem } from "./NavItem";
 import { SessionRail } from "./SessionRail";

frontend/web/src/components/TopBar.tsx

@@ -1,5 +1,6 @@
 import { useState } from "react";
-import { useAppStore, useCurrentMood, useCurrentPersona } from "../store/useAppStore";
+import { useAppStore } from "../store/useAppStore";
+import { useCurrentMood, useCurrentPersona } from "../store/personaSelectors";
 import { useModeStore } from "../store/useModeStore";
 import { applyTheme, readTheme, type ThemeMode } from "../lib/theme";
 import { personaAvatar } from "../lib/persona";

frontend/web/src/components/chat.tsx

@@ -1,6 +1,7 @@
 import { useState } from "react";
 import type { ChatMessage, Mode, PersonaRecord, ToolUsed } from "../lib/types";
-import { useAppStore, useCurrentPersona } from "../store/useAppStore";
+import { useAppStore } from "../store/useAppStore";
+import { useCurrentPersona } from "../store/personaSelectors";
 import { personaAvatar, resolveMessagePersona } from "../lib/persona";
 import { labelFor } from "../lib/enums";
 import { Tag } from "./primitives";