fix: Add timeout protection to window manager - fixes 4.5s UI freeze

Problem: EnumWindows was iterating through ALL windows on system
when EU wasn't running, causing 4.5s blocking delays every 5s.

Changes:
- _find_window_by_title: 100ms timeout, 500 window limit
- _find_window_by_process: 150ms timeout, 300 window limit
- Skip empty window titles (performance)
- Slow down focus detection to 60s when EU not found 3x

This should eliminate the 2s menu + 7s click delays.

core/main.py

@@ -526,9 +526,24 @@ class EUUtilityApp:
                                 debug_logger.info("MAIN", "EU unfocused - Activity Bar hidden")
                             except Exception as e:
                                 debug_logger.error("MAIN", f"Error hiding activity bar: {e}")
+                
+                # Reset fail count since we found EU
+                self._eu_not_found_count = 0
             else:
                 debug_logger.debug("MAIN", "EU window not found")
                 
+                # Track consecutive failures
+                self._eu_not_found_count = getattr(self, '_eu_not_found_count', 0) + 1
+                
+                # If EU not found for 3 consecutive checks (15 seconds), slow down polling
+                if self._eu_not_found_count >= 3:
+                    debug_logger.warn("MAIN", f"EU not found {self._eu_not_found_count} times - slowing down focus detection")
+                    # Slow down to once per minute when EU isn't running
+                    if hasattr(self, 'eu_focus_timer'):
+                        self.eu_focus_timer.stop()
+                        self.eu_focus_timer.start(60000)  # 60 seconds
+                        debug_logger.info("MAIN", "EU focus detection slowed to 60s interval")
+                
         except Exception as e:
             debug_logger.error("MAIN", f"Error in EU focus check: {e}")
         

core/window_manager.py

@@ -289,21 +289,38 @@ class WindowManager:
             self._last_update = current_time
     
     def _find_window_by_title(self, title: str) -> Optional[int]:
-        """Find window by title (partial match)."""
+        """Find window by title (partial match) - with timeout protection."""
         found_hwnd = [None]
+        start_time = time.time()
+        window_count = [0]
+        MAX_WINDOWS = 500  # Limit windows to check
+        MAX_TIME = 0.1  # 100ms timeout
         
         def callback(hwnd, extra):
+            # Check timeout
+            if time.time() - start_time > MAX_TIME:
+                return False  # Stop enumeration - timeout
+            
+            # Check window limit
+            window_count[0] += 1
+            if window_count[0] > MAX_WINDOWS:
+                return False  # Stop enumeration - too many windows
+            
             if not self.user32.IsWindowVisible(hwnd):
                 return True
             
-            # Get window text
+            # Quick check - skip windows with no title
             text = ctypes.create_unicode_buffer(256)
             self.user32.GetWindowTextW(hwnd, text, 256)
             window_title = text.value
             
+            if not window_title:  # Skip empty titles
+                return True
+            
+            # Fast case-insensitive check
             if title.lower() in window_title.lower():
                 found_hwnd[0] = hwnd
-                return False  # Stop enumeration
+                return False  # Stop enumeration - found!
             
             return True
         
@@ -313,10 +330,23 @@ class WindowManager:
         return found_hwnd[0]
     
     def _find_window_by_process(self, process_name: str) -> Optional[int]:
-        """Find window by process name."""
+        """Find window by process name - with timeout protection."""
         found_hwnd = [None]
+        start_time = time.time()
+        window_count = [0]
+        MAX_WINDOWS = 300  # Lower limit for process check (slower)
+        MAX_TIME = 0.15  # 150ms timeout
         
         def callback(hwnd, extra):
+            # Check timeout
+            if time.time() - start_time > MAX_TIME:
+                return False  # Stop enumeration - timeout
+            
+            # Check window limit
+            window_count[0] += 1
+            if window_count[0] > MAX_WINDOWS:
+                return False  # Stop enumeration - too many windows
+            
             if not self.user32.IsWindowVisible(hwnd):
                 return True
             
@@ -324,11 +354,17 @@ class WindowManager:
             pid = wintypes.DWORD()
             self.user32.GetWindowThreadProcessId(hwnd, ctypes.byref(pid))
             
-            # Check process name
+            if pid.value == 0:
-            proc_info = self._get_process_info(pid.value)
+                return True
-            if proc_info and process_name.lower() in proc_info.name.lower():
+            
-                found_hwnd[0] = hwnd
+            # Check process name (this is slower, so we limit more)
-                return False  # Stop enumeration
+            try:
+                proc_info = self._get_process_info(pid.value)
+                if proc_info and process_name.lower() in proc_info.name.lower():
+                    found_hwnd[0] = hwnd
+                    return False  # Stop enumeration - found!
+            except Exception:
+                pass  # Skip on error
             
             return True