refactor(web): router-based navigation, light theme, form config

- Replace Zustand activeView with React Router (NavLink + Routes)
- White/light modern theme with indigo accents
- Sidebar with Chinese labels under icons
- ConfigForm with individual form fields (no JSON textareas)
- Account switching with context injection into chat
- Fix duplicate conversation creation with useRef guard
- Asset gallery: smaller 6-column grid with date labels
- All components updated to light color scheme

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/client/src/components/chat/ChatInput.tsx

@@ -21,8 +21,8 @@ export function ChatInput({ onSend, disabled }: { onSend: (content: string) => v
   };
 
   return (
-    <div className="p-4 border-t border-zinc-800">
-      <div className="flex items-end gap-2 bg-zinc-900 rounded-lg border border-zinc-800 px-3 py-2">
+    <div className="p-4 border-t border-zinc-200 bg-white">
+      <div className="flex items-end gap-2 bg-zinc-50 rounded-xl border border-zinc-200 px-4 py-2.5 focus-within:border-indigo-300 transition-colors">
         <textarea
           ref={ref}
           value={input}
@@ -30,11 +30,11 @@ export function ChatInput({ onSend, disabled }: { onSend: (content: string) => v
           onKeyDown={handleKeyDown}
           rows={1}
           placeholder={disabled ? '等待回复中...' : '输入指令...'}
-          className="flex-1 bg-transparent text-sm resize-none outline-none placeholder:text-zinc-600"
+          className="flex-1 bg-transparent text-sm resize-none outline-none placeholder:text-zinc-400 text-zinc-700"
           disabled={disabled}
         />
-        <Button size="icon" variant="ghost" className="h-8 w-8" onClick={handleSend} disabled={disabled}>
-          <Send size={14} />
+        <Button size="icon" variant="ghost" className="h-8 w-8 text-zinc-400 hover:text-indigo-600" onClick={handleSend} disabled={disabled}>
+          <Send size={16} />
         </Button>
       </div>
     </div>