Add detailed timing logs for stream diagnostics

- Log stream start time, keepalive send time, first chunk time
- Log exact disconnect timing to diagnose premature closes
- Will help identify if qodercli is too slow or client is too aggressive

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: foxy1402

src/routes/chat.js

@@ -79,13 +79,17 @@ router.post('/', (req, res) => {
   if (stream) {
     setSSEHeaders(res);
 
+    const streamStartTime = Date.now();
+    console.log('[Stream Timing] Stream started at', streamStartTime);
+    
     // Disable socket timeout and enable keepalive for long-running streams
     req.socket.setTimeout(0);
     req.socket.setKeepAlive(true);
 
     // Send SSE comment immediately to keep connection alive (IDE compatibility)
     // Don't send an empty delta - some IDEs interpret that as end of stream
     res.write(': keep-alive\n\n');
+    console.log('[Stream Timing] Keepalive sent at', Date.now() - streamStartTime, 'ms');
 
     // Explicitly flush the response buffer
     if (typeof res.flush === 'function') res.flush();
@@ -103,6 +107,10 @@ router.post('/', (req, res) => {
         const toolCalls = extractToolCalls(data.message?.content);
         const finishReason = data.message?.stop_reason || null;
 
+        if (!hasReceivedData) {
+          console.log('[Stream Timing] First chunk received at', Date.now() - streamStartTime, 'ms');
+        }
+        
         if (finishReason) lastFinishReason = finishReason;
 
         if (toolCalls && toolCalls.length > 0) {
@@ -142,6 +150,8 @@ router.post('/', (req, res) => {
     });
 
     req.on('close', () => {
+      const disconnectTime = Date.now() - streamStartTime;
+      console.log('[Stream Timing] Client disconnected at', disconnectTime, 'ms');
       if (!hasReceivedData) {
         console.log('[chat/completions] Client disconnected before receiving any data');
       }