Initial commit: Bifrost accessible fediverse client

- Full ActivityPub support for Pleroma, GoToSocial, and Mastodon
- Screen reader optimized interface with PySide6
- Timeline switching with tabs and keyboard shortcuts (Ctrl+1-4)
- Threaded conversation navigation with expand/collapse
- Cross-platform desktop notifications via plyer
- Customizable sound pack system with audio feedback
- Complete keyboard navigation and accessibility features
- XDG Base Directory compliant configuration
- Multiple account support with OAuth authentication

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/notifications/notification_manager.py

@@ -0,0 +1,109 @@
+"""
+Desktop notification manager using plyer
+"""
+
+from typing import Optional
+from plyer import notification
+from config.settings import SettingsManager
+
+
+class NotificationManager:
+    """Manages desktop notifications for Bifrost"""
+    
+    def __init__(self, settings: SettingsManager):
+        self.settings = settings
+        
+    def is_enabled(self, notification_type: str = None) -> bool:
+        """Check if notifications are enabled globally or for specific type"""
+        if not self.settings.get_bool('notifications', 'enabled', True):
+            return False
+            
+        if notification_type:
+            return self.settings.get_bool('notifications', notification_type, True)
+        return True
+        
+    def show_notification(self, title: str, message: str, notification_type: str = None):
+        """Show a desktop notification"""
+        if not self.is_enabled(notification_type):
+            return
+            
+        try:
+            notification.notify(
+                title=title,
+                message=message,
+                app_name="Bifrost",
+                timeout=5
+            )
+        except Exception as e:
+            print(f"Failed to show notification: {e}")
+            
+    def notify_direct_message(self, sender: str, message_preview: str):
+        """Show notification for direct message"""
+        if not self.is_enabled('direct_messages'):
+            return
+            
+        self.show_notification(
+            title=f"Direct message from {sender}",
+            message=message_preview,
+            notification_type='direct_messages'
+        )
+        
+    def notify_mention(self, sender: str, post_preview: str):
+        """Show notification for mention"""
+        if not self.is_enabled('mentions'):
+            return
+            
+        self.show_notification(
+            title=f"{sender} mentioned you",
+            message=post_preview,
+            notification_type='mentions'
+        )
+        
+    def notify_boost(self, sender: str, post_preview: str):
+        """Show notification for boost/reblog"""
+        if not self.is_enabled('boosts'):
+            return
+            
+        self.show_notification(
+            title=f"{sender} boosted your post",
+            message=post_preview,
+            notification_type='boosts'
+        )
+        
+    def notify_favorite(self, sender: str, post_preview: str):
+        """Show notification for favorite"""
+        if not self.is_enabled('favorites'):
+            return
+            
+        self.show_notification(
+            title=f"{sender} favorited your post",
+            message=post_preview,
+            notification_type='favorites'
+        )
+        
+    def notify_follow(self, follower: str):
+        """Show notification for new follower"""
+        if not self.is_enabled('follows'):
+            return
+            
+        self.show_notification(
+            title="New follower",
+            message=f"{follower} started following you",
+            notification_type='follows'
+        )
+        
+    def notify_timeline_update(self, count: int, timeline_type: str = "timeline"):
+        """Show notification for timeline updates"""
+        if not self.is_enabled('timeline_updates'):
+            return
+            
+        if count == 1:
+            message = f"1 new post in your {timeline_type}"
+        else:
+            message = f"{count} new posts in your {timeline_type}"
+            
+        self.show_notification(
+            title="Timeline updated",
+            message=message,
+            notification_type='timeline_updates'
+        )