feat: LLM intent router, direct chat execution, and Memory V2 light intervention

Wire chat intent routing with direct_chat on regular sessions, skill-selected
short-circuit to Agent, memory light/heavy intervention tiers, and fix direct
chat UI stuck streaming after completion.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/ChatPanel.tsx

@@ -172,6 +172,7 @@ export function ChatPanel({
   const [uploadingImage, setUploadingImage] = useState(false);
   const [imageError, setImageError] = useState<string | null>(null);
   const [voiceStopSignal, setVoiceStopSignal] = useState(0);
+  const pendingSkillRef = useRef<string | null>(null);
   const [randomPrompt] = useState(
     () => CHAT_PLACEHOLDER_PROMPTS[Math.floor(Math.random() * CHAT_PLACEHOLDER_PROMPTS.length)],
   );
@@ -432,9 +433,11 @@ export function ChatPanel({
     return { accepted, message };
   }, [pendingImageBytes, pendingImages.length]);
 
-  const submitText = useCallback(async (textOverride?: string) => {
+  const submitText = useCallback(async (textOverride?: string, skillIdOverride?: string) => {
     const baseText = typeof textOverride === 'string' ? textOverride : input;
     const trimmed = baseText.trim();
+    const selectedChatSkill = skillIdOverride ?? pendingSkillRef.current ?? undefined;
+    pendingSkillRef.current = null;
     if ((!trimmed && pendingImages.length === 0) || voiceDisabled) return;
     if (pendingImages.length > 0 && !onUploadImage) {
       setImageError('当前会话暂不支持图片发送');
@@ -518,6 +521,7 @@ export function ChatPanel({
       await onSubmit(trimmed, imagesToSend, previewImagesToSend, {
         messageId: outgoingMessageId,
         forceDeepReasoning,
+        selectedChatSkill,
       });
       uploadedImages.forEach(revokePendingImage);
       setPendingImages([]);
@@ -823,7 +827,10 @@ export function ChatPanel({
               skills={chatSkills}
               disabled={voiceDisabled}
               onSelect={submitText}
-              onPrefill={setInput}
+              onPrefill={(prompt, skillId) => {
+                pendingSkillRef.current = skillId ?? null;
+                setInput(prompt);
+              }}
             />
           )}
           {!showHomeWelcome && (

src/components/ChatSkillPicker.tsx

@@ -10,8 +10,8 @@ export function ChatSkillPicker({
 }: {
   skills: ChatSkillOption[];
   disabled?: boolean;
-  onSelect: (prompt: string) => void | Promise<void>;
-  onPrefill?: (prompt: string) => void;
+  onSelect: (prompt: string, skillId?: string) => void | Promise<void>;
+  onPrefill?: (prompt: string, skillId?: string) => void;
 }) {
   const [open, setOpen] = useState(false);
   const wrapRef = useRef<HTMLDivElement>(null);
@@ -40,10 +40,10 @@ export function ChatSkillPicker({
     setOpen(false);
     const prompt = skill.buildPrompt(skill.skillName);
     if (skill.prefillOnly) {
-      onPrefill?.(prompt);
+      onPrefill?.(prompt, skill.id);
       return;
     }
-    void onSelect(prompt);
+    void onSelect(prompt, skill.id);
   };
 
   return (