feat: 知识库实体筛选、技能白名单收紧、嵌入主题与提问组件优化

- 知识库笔记列表支持按实体精确筛选（路由/服务/仓储层透传，关系图索引查询）
- 自定义智能体技能白名单在 skill_view 与 skill_manage 的 list/view 别名上同样生效；
  config 未声明 skills 时视为无可见技能
- 嵌入圆桌主题解析默认深蓝，强制主题期间不再写 localStorage 覆盖主站选择
- 智能体提问建议拆出 agent-question-chips 组件，编辑器与详情面板联动优化
- 新增 qa-client 问答测试脚本

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend-web/src/contexts/ThemeContext.tsx

@@ -128,7 +128,10 @@ interface ThemeProviderProps {
 }
 
 export const ThemeProvider: React.FC<ThemeProviderProps> = ({ children }) => {
-  const { resolvedTheme, setTheme: setNextTheme } = useNextTheme();
+  // forcedTheme：嵌入路由 / landing 由 AppProviders 强制的主题。强制期间
+  // 它决定渲染，且本组件不得写 localStorage（嵌入子应用与主站同域共享
+  // 存储，写入会覆盖用户在主站的选择）。
+  const { resolvedTheme, forcedTheme, setTheme: setNextTheme } = useNextTheme();
   const [mounted, setMounted] = useState(false);
   // Admin-configured global default. If the user hasn't explicitly chosen
   // a theme yet, this value drives the rendered theme — and re-syncs on
@@ -144,7 +147,7 @@ export const ThemeProvider: React.FC<ThemeProviderProps> = ({ children }) => {
   // 注意：不要在这里强制写入一个 fallback —— 那会让 next-themes 视作
   // 「用户已选过」，admin 默认就再也注入不进来了。
   useEffect(() => {
-    if (!mounted) return;
+    if (!mounted || forcedTheme) return;
     const current = localStorage.getItem(STORAGE_KEY);
     const legacy = localStorage.getItem('theme');
 
@@ -162,24 +165,25 @@ export const ThemeProvider: React.FC<ThemeProviderProps> = ({ children }) => {
     if (legacy) {
       localStorage.removeItem('theme');
     }
-  }, [mounted, setNextTheme]);
+  }, [mounted, forcedTheme, setNextTheme]);
 
   // Boot-time sync: when the user has never picked a theme themselves,
   // apply whatever the admin configured. Re-runs whenever the admin
   // setting changes (so a logged-in user sees the new default after
   // refreshing without having to clear cookies).
   useEffect(() => {
-    if (!mounted) return;
+    if (!mounted || forcedTheme) return;
     if (hasExplicitChoice()) return;
     const adminDefault = appearance?.default_theme;
     if (!adminDefault) return;
     if (resolvedTheme !== adminDefault) {
       setNextTheme(adminDefault);
     }
-  }, [mounted, appearance?.default_theme, resolvedTheme, setNextTheme]);
+  }, [mounted, forcedTheme, appearance?.default_theme, resolvedTheme, setNextTheme]);
 
+  const effectiveTheme = forcedTheme ?? resolvedTheme;
   const theme: ThemeType = mounted
-    ? resolvedTheme === 'dark'
+    ? effectiveTheme === 'dark'
       ? 'dark'
       : 'light'
     : readPersistedTheme();