feat(web): 多主题系统 — 4 套主题 + CSS 变量 + Ant Design 动态主题

- CSS 变量层: :root 默认 blue, [data-theme] 覆盖 warm/dark/emerald
- Ant Design: ConfigProvider 按 ThemeName 切换 token + algorithm
- ThemeSwitcher: 下拉面板含 4 主题色块预览 + localStorage 持久化
- useThemeMode: 从 store 读取主题名替代色值比对（修复 33 页面暗色失效）
- index.html: 添加 Noto Serif SC 字体（warm 主题衬线标题）

apps/web/src/stores/app.ts

@@ -1,15 +1,64 @@
 import { create } from 'zustand';
 
+export type ThemeName = 'blue' | 'warm' | 'dark' | 'emerald';
+
+export interface ThemeOption {
+  key: ThemeName;
+  label: string;
+  desc: string;
+  preview: { primary: string; bg: string; surface: string };
+}
+
+export const THEME_OPTIONS: ThemeOption[] = [
+  {
+    key: 'blue',
+    label: '信任蓝',
+    desc: '专业沉稳 · 企业风格',
+    preview: { primary: '#2563EB', bg: '#F8FAFC', surface: '#FFFFFF' },
+  },
+  {
+    key: 'warm',
+    label: '温润东方',
+    desc: '暖色人文 · 医疗关怀',
+    preview: { primary: '#C4623A', bg: '#F5F0EB', surface: '#FFFFFF' },
+  },
+  {
+    key: 'dark',
+    label: '深邃夜色',
+    desc: '暗色护眼 · 深度专注',
+    preview: { primary: '#60A5FA', bg: '#0F172A', surface: '#1E293B' },
+  },
+  {
+    key: 'emerald',
+    label: '翡翠清雅',
+    desc: '清新自然 · 健康生机',
+    preview: { primary: '#5B7A5E', bg: '#F4F7F4', surface: '#FFFFFF' },
+  },
+];
+
+const STORAGE_KEY = 'hms-theme';
+
+function loadTheme(): ThemeName {
+  try {
+    const saved = localStorage.getItem(STORAGE_KEY);
+    if (saved && THEME_OPTIONS.some((t) => t.key === saved)) return saved as ThemeName;
+  } catch {}
+  return 'blue';
+}
+
 interface AppState {
-  theme: 'light' | 'dark';
+  theme: ThemeName;
   sidebarCollapsed: boolean;
   toggleSidebar: () => void;
-  setTheme: (theme: 'light' | 'dark') => void;
+  setTheme: (theme: ThemeName) => void;
 }
 
 export const useAppStore = create<AppState>((set) => ({
-  theme: 'light',
+  theme: loadTheme(),
   sidebarCollapsed: false,
   toggleSidebar: () => set((s) => ({ sidebarCollapsed: !s.sidebarCollapsed })),
-  setTheme: (theme) => set({ theme }),
+  setTheme: (theme) => {
+    try { localStorage.setItem(STORAGE_KEY, theme); } catch {}
+    set({ theme });
+  },
 }));