feat: Enhance summary hook to include last user message from transcript (#95)

* feat: Enhance summary hook to include last user message from transcript

- Added functionality to extract the last user message from a JSONL transcript file in the summary hook.
- Updated the summary hook to send the last user message along with the summary request.
- Modified the SDKSession interface to include an optional last_user_message field.
- Updated the summary prompt to incorporate the last user message in the output format.
- Refactored worker service to handle the last user message in the summarize queue.
- Enhanced session manager to track and broadcast processing status based on active sessions and queue depth.
- Improved error handling and logging for better traceability during transcript reading and processing.

* feat(worker): enhance processing status broadcasting and session management

- Added immediate broadcasting of processing status when a prompt is received.
- Implemented logging for generator completion in multiple locations.
- Updated `broadcastProcessingStatus` to include queue depth and active session count in logs.
- Modified session iterator to stop yielding messages after a summary is yielded, with appropriate logging.

src/services/worker/SDKAgent.ts

@@ -188,7 +188,8 @@ export class SDKAgent {
               id: session.sessionDbId,
               sdk_session_id: session.sdkSessionId,
               project: session.project,
-              user_prompt: session.userPrompt
+              user_prompt: session.userPrompt,
+              last_user_message: message.last_user_message || ''
             })
           },
           session_id: session.claudeSessionId,
@@ -351,9 +352,9 @@ export class SDKAgent {
       }
     }
 
-    // Check and stop spinner after processing (debounced)
-    if (worker && typeof worker.checkAndStopSpinner === 'function') {
-      worker.checkAndStopSpinner();
+    // Broadcast activity status after processing (queue may have changed)
+    if (worker && typeof worker.broadcastProcessingStatus === 'function') {
+      worker.broadcastProcessingStatus();
     }
   }