feat: Add status bar with update status indicator

Status bar implementation:
- Status bar at bottom of main window
- Update status label with emoji support
- set_update_status() method for updates:
  -  Checking for updates
  -  Update available
  -  Downloading update
  -  Update failed
  - Clean status display

Test coverage:
- 8 new tests for status bar
- Test creation and initialization
- Test status updates with/without emoji
- Test all status states (checking, available, downloading, error)
- All 154 tests passing, 86% coverage

Enables visual feedback during update operations

src/webdrop_bridge/ui/main_window.py

@@ -4,7 +4,7 @@ from pathlib import Path
 from typing import Optional
 
 from PySide6.QtCore import QSize, Qt, QUrl, Signal
-from PySide6.QtWidgets import QMainWindow, QToolBar, QVBoxLayout, QWidget
+from PySide6.QtWidgets import QMainWindow, QToolBar, QVBoxLayout, QWidget, QLabel, QStatusBar
 
 from webdrop_bridge.config import Config
 from webdrop_bridge.core.drag_interceptor import DragInterceptor
@@ -208,6 +208,9 @@ class MainWindow(QMainWindow):
         # Create menu bar
         self._create_menu_bar()
 
+        # Create status bar
+        self._create_status_bar()
+
         # Create drag interceptor
         self.drag_interceptor = DragInterceptor()
 
@@ -358,6 +361,27 @@ class MainWindow(QMainWindow):
         check_updates_action = help_menu.addAction("Check for Updates...")
         check_updates_action.triggered.connect(self._on_check_for_updates)
 
+    def _create_status_bar(self) -> None:
+        """Create status bar with update status indicator."""
+        self.status_bar = self.statusBar()
+        
+        # Update status label
+        self.update_status_label = QLabel("Ready")
+        self.update_status_label.setStyleSheet("margin-right: 10px;")
+        self.status_bar.addPermanentWidget(self.update_status_label)
+
+    def set_update_status(self, status: str, emoji: str = "") -> None:
+        """Update the status bar with update information.
+        
+        Args:
+            status: Status text to display
+            emoji: Optional emoji prefix (🔄, ✅, ⬇️, ⚠️)
+        """
+        if emoji:
+            self.update_status_label.setText(f"{emoji} {status}")
+        else:
+            self.update_status_label.setText(status)
+
     def _on_check_for_updates(self) -> None:
         """Handle check for updates menu action.