perf: reduce frontend memory pressure and startup cost

Limit long-lived page and component retention while virtualizing large card views to keep runtime memory lower. Defer heavy editor, chart, workflow, calendar, and icon code so the app loads less JavaScript up front.

src/utils/themeManager.ts

@@ -9,6 +9,7 @@ class ThemeManager {
   private themes: Map<string, ThemeConfig> = new Map()
   private currentTheme: string = 'default'
   private loadedLinks: Map<string, HTMLLinkElement> = new Map()
+  private themeListeners: Map<(theme: string) => void, EventListener> = new Map()
 
   constructor() {
     // 注册所有可用主题
@@ -190,18 +191,29 @@ class ThemeManager {
    * 监听主题变更事件
    */
   onThemeChange(callback: (theme: string) => void): void {
-    document.addEventListener('themechange', (event: any) => {
-      callback(event.detail.theme)
-    })
+    if (this.themeListeners.has(callback)) {
+      return
+    }
+
+    const listener: EventListener = event => {
+      callback((event as CustomEvent<{ theme: string }>).detail.theme)
+    }
+
+    this.themeListeners.set(callback, listener)
+    document.addEventListener('themechange', listener)
   }
 
   /**
    * 移除主题变更监听器
    */
   offThemeChange(callback: (theme: string) => void): void {
-    document.removeEventListener('themechange', (event: any) => {
-      callback(event.detail.theme)
-    })
+    const listener = this.themeListeners.get(callback)
+    if (!listener) {
+      return
+    }
+
+    document.removeEventListener('themechange', listener)
+    this.themeListeners.delete(callback)
   }
 }