fix(gui): SQLite thread safety - use queue for cross-thread database access

- LogWatcher callbacks now queue events instead of direct DB access
- Main thread processes queue every 100ms
- Fixes 'SQLite objects created in a thread can only be used in that same thread' error
- Loot will now be properly recorded to database

ui/main_window.py

@@ -236,10 +236,20 @@ class MainWindow(QMainWindow):
         self.log_watcher: Optional[LogWatcher] = None
         self._log_watcher_task = None
         
+        # Thread-safe queue for cross-thread communication
+        from queue import Queue
+        self._event_queue = Queue()
+        
+        # Timer to process queued events in main thread
+        self._queue_timer = QTimer(self)
+        self._queue_timer.timeout.connect(self._process_queued_events)
+        self._queue_timer.start(100)  # Check every 100ms
+        
         # State
         self.current_project: Optional[Project] = None
         self.session_state = SessionState.IDLE
         self.current_session_id: Optional[int] = None
+        self._current_db_session_id: Optional[int] = None
         
         # Setup UI
         self.setup_ui()
@@ -904,27 +914,28 @@ class MainWindow(QMainWindow):
             """Handle loot events."""
             item_name = event.data.get('item_name', 'Unknown')
             value_ped = event.data.get('value_ped', Decimal('0.0'))
+            quantity = event.data.get('quantity', 1)
             
             # Skip Universal Ammo
             if item_name == 'Universal Ammo':
                 return
             
-            # Record to database
+            # Queue database write for main thread (SQLite thread safety)
             if self._current_db_session_id:
-                loot = LootEvent(
-                    item_name=item_name,
-                    quantity=event.data.get('quantity', 1),
-                    value_ped=value_ped,
-                    event_type='regular',
-                    raw_log_line=event.raw_line
-                )
-                self.project_manager.record_loot(loot)
+                self._event_queue.put({
+                    'type': 'loot',
+                    'session_id': self._current_db_session_id,
+                    'item_name': item_name,
+                    'quantity': quantity,
+                    'value_ped': value_ped,
+                    'raw_line': event.raw_line
+                })
             
-            # Update HUD
+            # Update HUD (thread-safe)
             self.hud.on_loot_event(item_name, value_ped)
             
-            # Log to UI
-            self.log_info("Loot", f"{item_name} x{event.data.get('quantity', 1)} ({value_ped} PED)")
+            # Log to UI (main thread only - use signal/slot or queue)
+            # We'll log this in _process_queued_events instead
         
         def on_global(event):
             """Handle global events."""
@@ -1017,6 +1028,34 @@ class MainWindow(QMainWindow):
             self._log_watcher_thread = None
             self.log_info("LogWatcher", "Stopped")
     
+    def _process_queued_events(self):
+        """Process events from the queue in the main thread (SQLite thread safety)."""
+        from core.project_manager import LootEvent
+        from decimal import Decimal
+        
+        processed = 0
+        while not self._event_queue.empty() and processed < 10:  # Process max 10 per tick
+            try:
+                event = self._event_queue.get_nowait()
+                
+                if event['type'] == 'loot':
+                    # Record to database (now in main thread - safe)
+                    loot = LootEvent(
+                        item_name=event['item_name'],
+                        quantity=event['quantity'],
+                        value_ped=event['value_ped'],
+                        event_type='regular',
+                        raw_log_line=event['raw_line']
+                    )
+                    self.project_manager.record_loot(loot)
+                    
+                    # Log to UI
+                    self.log_info("Loot", f"{event['item_name']} x{event['quantity']} ({event['value_ped']} PED)")
+                
+                processed += 1
+            except Exception as e:
+                self.log_error("EventQueue", f"Error processing event: {e}")
+    
     def on_start_session(self):
         """Handle start session button."""
         if self.current_project and self.session_state == SessionState.IDLE: