feat: implement desktop notifications with comprehensive filtering

Implemented Phase 10 (Desktop Notifications) with three stages:
notify-rust integration, smart filtering, and production polish.

Stage 1 - Base Implementation:
- Add NotificationManager module (src/notifications.rs, 350+ lines)
- Integrate notify-rust 4.11 with feature flag "notifications"
- Implement NotificationsConfig in config.toml (enabled, only_mentions, show_preview)
- Add notification_manager field to TdClient
- Create configure_notifications() method for config integration
- Hook into handle_new_message_update() to send notifications
- Send notifications for messages outside current chat
- Format notification body with sender name and message preview

Stage 2 - Smart Filtering:
- Sync muted chats from Telegram (sync_muted_chats method)
- Filter muted chats from notifications automatically
- Add MessageInfo::has_mention() to detect @username mentions
- Implement only_mentions filter (notify only when mentioned)
- Beautify media labels with emojis (📷 📹 🎤 🎨 📎 etc.)
- Support 10+ media types in notification preview

Stage 3 - Production Polish:
- Add graceful error handling (no panics on notification failure)
- Implement comprehensive logging (tracing::debug!/warn!)
- Add timeout_ms configuration (0 = system default)
- Add urgency configuration (low/normal/critical, Linux only)
- Platform-specific #[cfg] for urgency support
- Log all notification skip reasons at debug level

Hotkey Change:
- Move profile view from 'i' to Ctrl+i to avoid conflicts

Technical Details:
- Cross-platform support (macOS, Linux, Windows)
- Feature flag for optional notifications support
- Graceful fallback when notifications unavailable
- LRU-friendly muted chats sync
- Test coverage for all core notification logic
- All 75 tests passing

Files Changed:
- NEW: src/notifications.rs - Complete NotificationManager
- NEW: config.example.toml - Example configuration with notifications
- Modified: Cargo.toml - Add notify-rust 4.11 dependency
- Modified: src/config/mod.rs - Add NotificationsConfig struct
- Modified: src/tdlib/types.rs - Add has_mention() method
- Modified: src/tdlib/client.rs - Add notification integration
- Modified: src/tdlib/update_handlers.rs - Hook notifications
- Modified: src/config/keybindings.rs - Change profile to Ctrl+i
- Modified: tests/* - Add notification config to tests

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/tdlib/client.rs

@@ -15,6 +15,7 @@ use super::messages::MessageManager;
 use super::reactions::ReactionManager;
 use super::types::{ChatInfo, FolderInfo, MessageInfo, NetworkState, ProfileInfo, UserOnlineStatus};
 use super::users::UserCache;
+use crate::notifications::NotificationManager;
 
 /// TDLib client wrapper for Telegram integration.
 ///
@@ -52,6 +53,7 @@ pub struct TdClient {
     pub message_manager: MessageManager,
     pub user_cache: UserCache,
     pub reaction_manager: ReactionManager,
+    pub notification_manager: NotificationManager,
 
     // Состояние сети
     pub network_state: NetworkState,
@@ -93,10 +95,27 @@ impl TdClient {
             message_manager: MessageManager::new(client_id),
             user_cache: UserCache::new(client_id),
             reaction_manager: ReactionManager::new(client_id),
+            notification_manager: NotificationManager::new(),
             network_state: NetworkState::Connecting,
         }
     }
 
+    /// Configures notification manager from app config
+    pub fn configure_notifications(&mut self, config: &crate::config::NotificationsConfig) {
+        self.notification_manager.set_enabled(config.enabled);
+        self.notification_manager.set_only_mentions(config.only_mentions);
+        self.notification_manager.set_timeout(config.timeout_ms);
+        self.notification_manager.set_urgency(config.urgency.clone());
+        // Note: show_preview is used when formatting notification body
+    }
+
+    /// Synchronizes muted chats from Telegram to notification manager.
+    ///
+    /// Should be called after chats are loaded to ensure muted chats don't trigger notifications.
+    pub fn sync_notification_muted_chats(&mut self) {
+        self.notification_manager.sync_muted_chats(&self.chat_manager.chats);
+    }
+
     // Делегирование к auth
 
     /// Sends phone number for authentication.

src/tdlib/client_impl.rs

@@ -263,6 +263,11 @@ impl TdClientTrait for TdClient {
         self.user_cache_mut()
     }
 
+    // ============ Notification methods ============
+    fn sync_notification_muted_chats(&mut self) {
+        self.sync_notification_muted_chats()
+    }
+
     // ============ Update handling ============
     fn handle_update(&mut self, update: Update) {
         self.handle_update(update)

src/tdlib/trait.rs

@@ -120,6 +120,9 @@ pub trait TdClientTrait: Send {
     fn set_main_chat_list_position(&mut self, position: i32);
     fn user_cache_mut(&mut self) -> &mut UserCache;
 
+    // ============ Notification methods ============
+    fn sync_notification_muted_chats(&mut self);
+
     // ============ Update handling ============
     fn handle_update(&mut self, update: Update);
 }

src/tdlib/types.rs

@@ -1,3 +1,4 @@
+use tdlib_rs::enums::TextEntityType;
 use tdlib_rs::types::TextEntity;
 
 use crate::types::{ChatId, MessageId};
@@ -192,6 +193,16 @@ impl MessageInfo {
         self.state.can_be_deleted_for_all_users
     }
 
+    /// Checks if the message contains a mention (@username or user mention)
+    pub fn has_mention(&self) -> bool {
+        self.content.entities.iter().any(|entity| {
+            matches!(
+                entity.r#type,
+                TextEntityType::Mention | TextEntityType::MentionName(_)
+            )
+        })
+    }
+
     pub fn reply_to(&self) -> Option<&ReplyInfo> {
         self.interactions.reply_to.as_ref()
     }
@@ -475,6 +486,39 @@ mod tests {
         assert!(message.can_be_edited());
         assert!(message.can_be_deleted_for_all_users());
     }
+
+    #[test]
+    fn test_message_has_mention() {
+        // Message without mentions
+        let message = MessageBuilder::new(MessageId::new(1))
+            .text("Hello world")
+            .build();
+        assert!(!message.has_mention());
+
+        // Message with @mention
+        let message_with_mention = MessageBuilder::new(MessageId::new(2))
+            .text("Hello @user")
+            .entities(vec![TextEntity {
+                offset: 6,
+                length: 5,
+                r#type: TextEntityType::Mention,
+            }])
+            .build();
+        assert!(message_with_mention.has_mention());
+
+        // Message with MentionName
+        let message_with_mention_name = MessageBuilder::new(MessageId::new(3))
+            .text("Hello John")
+            .entities(vec![TextEntity {
+                offset: 6,
+                length: 4,
+                r#type: TextEntityType::MentionName(
+                    tdlib_rs::types::TextEntityTypeMentionName { user_id: 123 },
+                ),
+            }])
+            .build();
+        assert!(message_with_mention_name.has_mention());
+    }
 }
 
 #[derive(Debug, Clone)]

src/tdlib/update_handlers.rs

@@ -19,12 +19,29 @@ use super::types::ReactionInfo;
 
 /// Обрабатывает Update::NewMessage - добавление нового сообщения
 pub fn handle_new_message_update(client: &mut TdClient, new_msg: UpdateNewMessage) {
-    // Добавляем новое сообщение если это текущий открытый чат
     let chat_id = ChatId::new(new_msg.message.chat_id);
+
+    // Если сообщение НЕ для текущего открытого чата - отправляем уведомление
     if Some(chat_id) != client.current_chat_id() {
+        // Find and clone chat info to avoid borrow checker issues
+        if let Some(chat) = client.chats().iter().find(|c| c.id == chat_id).cloned() {
+            let msg_info = crate::tdlib::message_converter::convert_message(client, &new_msg.message, chat_id);
+
+            // Get sender name (from message or user cache)
+            let sender_name = msg_info.sender_name();
+
+            // Send notification
+            let _ = client.notification_manager.notify_new_message(
+                &chat,
+                &msg_info,
+                sender_name,
+            );
+        }
         return;
     }
 
+    // Добавляем новое сообщение если это текущий открытый чат
+
     let msg_info = crate::tdlib::message_converter::convert_message(client, &new_msg.message, chat_id);
     let msg_id = msg_info.id();
     let is_incoming = !msg_info.is_outgoing();