docs: Add plan for Project-Specific Agent Instructions feature

- Create comprehensive plan document for agent instructions text area
- Define requirements, acceptance criteria, and technical implementation
- Include UI/UX mockups and testing strategy
- Plan discovered during FILES panel implementation
- Addresses need for project-specific acceptance criteria

gadget-code/frontend/src/components/FileTree.tsx

@@ -53,11 +53,17 @@ export default function FileTree({ workspaceMode, onFileSelect }: FileTreeProps)
       return;
     }
 
-    setState(prev => ({
+    setState(prev => {
+      const newLoading = new Set(prev.loadingPaths);
+      newLoading.add(path);
+      const newErrors = new Map(prev.errors);
+      newErrors.delete(path);
+      return {
         ...prev,
-      loadingPaths: new Set(prev.loadingPaths).add(path),
-      errors: new Map(prev.errors).delete(path),
-    }));
+        loadingPaths: newLoading,
+        errors: newErrors,
+      };
+    });
 
     try {
       const result = await socketClient.requestFileTree({
@@ -67,24 +73,42 @@ export default function FileTree({ workspaceMode, onFileSelect }: FileTreeProps)
       });
 
       if (result.success && result.entries) {
-        setState(prev => ({
+        setState(prev => {
+          const newCache = new Map(prev.directoryCache);
+          newCache.set(path, result.entries!);
+          const newLoading = new Set(prev.loadingPaths);
+          newLoading.delete(path);
+          return {
             ...prev,
-          directoryCache: new Map(prev.directoryCache).set(path, result.entries!),
-          loadingPaths: new Set(prev.loadingPaths).delete(path),
-        }));
+            directoryCache: newCache,
+            loadingPaths: newLoading,
+          };
+        });
       } else {
-        setState(prev => ({
+        setState(prev => {
+          const newErrors = new Map(prev.errors);
+          newErrors.set(path, result.error || 'Failed to load directory');
+          const newLoading = new Set(prev.loadingPaths);
+          newLoading.delete(path);
+          return {
             ...prev,
-          errors: new Map(prev.errors).set(path, result.error || 'Failed to load directory'),
-          loadingPaths: new Set(prev.loadingPaths).delete(path),
-        }));
+            errors: newErrors,
+            loadingPaths: newLoading,
+          };
+        });
       }
     } catch (error) {
-      setState(prev => ({
+      setState(prev => {
+        const newErrors = new Map(prev.errors);
+        newErrors.set(path, error instanceof Error ? error.message : 'Unknown error');
+        const newLoading = new Set(prev.loadingPaths);
+        newLoading.delete(path);
+        return {
           ...prev,
-        errors: new Map(prev.errors).set(path, error instanceof Error ? error.message : 'Unknown error'),
-        loadingPaths: new Set(prev.loadingPaths).delete(path),
-      }));
+          errors: newErrors,
+          loadingPaths: newLoading,
+        };
+      });
     }
   }, [state.directoryCache, state.loadingPaths]);
 

gadget-code/src/lib/code-session.ts

@@ -436,12 +436,12 @@ export class CodeSession extends SocketSession {
     }
     try {
       const droneSession = SocketService.getDroneSession(this.selectedDrone);
-      droneSession.socket.emit("fileTreeRequest", args, (success, data) => {
+      droneSession.socket.emit("fileTreeRequest", args, (success: boolean, data: { entries?: FileTreeEntry[]; error?: string }) => {
         // Forward response to IDE
-        if (success && data.entries) {
+        if (success && data?.entries) {
           this.socket.emit("fileTreeResponse", args.path || "", data.entries);
         } else {
-          this.socket.emit("fileTreeResponse", args.path || "", [], data.error);
+          this.socket.emit("fileTreeResponse", args.path || "", [], data?.error);
         }
         cb(success, data);
       });

packages/api/src/messages/socket.ts

@@ -120,6 +120,7 @@ export interface ServerToClientEvents {
   processWorkOrder: ProcessWorkOrderMessage;
   crashRecoveryResponse: CrashRecoveryResponseMessage;
   requestTermination: RequestTerminationMessage;
+  fileTreeRequest: FileTreeRequestMessage;
 
   /*
    * gadget-code:web => gadget-code:ide