debug(gemini): add /api/chat/debug endpoint to capture raw response

vibn-frontend/app/api/chat/debug/route.ts

@@ -0,0 +1,14 @@
+import { NextResponse } from 'next/server';
+
+// Global variable to store the last raw Gemini response for easy debugging
+let lastGeminiResponse: any = null;
+
+export function setLastGeminiResponse(resp: any) {
+  lastGeminiResponse = resp;
+}
+
+export async function GET() {
+  return NextResponse.json({
+    lastResponse: lastGeminiResponse || "No requests captured yet since last deploy. Send a message from the desktop first."
+  });
+}

vibn-frontend/lib/ai/gemini-chat.ts

@@ -138,6 +138,14 @@ export async function callGeminiChat(opts: {
       JSON.stringify(response, null, 2),
     );
 
+    try {
+      const { setLastGeminiResponse } =
+        await import("../../app/api/chat/debug/route");
+      setLastGeminiResponse(response);
+    } catch (e) {
+      console.warn("Failed to set debug response:", e);
+    }
+
     let text = "";
     let thoughts = "";
     const toolCalls: ToolCall[] = [];