Enhance Telegram service with multi-format support and chunking

Renamed send_telegram_media_group to send_telegram_notification with expanded capabilities:
- Text messages (when urls is empty)
- Single photo/video (uses sendPhoto/sendVideo APIs)
- Media groups (uses sendMediaGroup API)
- Automatic chunking for unlimited media URLs
- Smart optimization: single-item chunks use appropriate single-item APIs

New parameters:
- max_group_size (2-10, default 10): control items per media group
- chunk_delay (0-60000ms, default 0): delay between chunks for rate limiting
- disable_web_page_preview: disable link previews in text messages

The service now intelligently selects the most efficient Telegram API endpoint based on content type and chunk size, with comprehensive error handling and logging.

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

README.md

@@ -32,7 +32,7 @@ A Home Assistant custom integration that monitors [Immich](https://immich.app/)
 - **Services** - Custom service calls:
   - `immich_album_watcher.refresh` - Force immediate data refresh
   - `immich_album_watcher.get_recent_assets` - Get recent assets from an album
-  - `immich_album_watcher.send_telegram_media_group` - Send media to Telegram chats
+  - `immich_album_watcher.send_telegram_notification` - Send text, photo, video, or media group to Telegram
 - **Share Link Management** - Button entities to create and delete share links:
   - Create/delete public (unprotected) share links
   - Create/delete password-protected share links
@@ -115,12 +115,49 @@ data:
   count: 10
 ```
 
-### Send Telegram Media Group
+### Send Telegram Notification
 
-Send media URLs to a Telegram chat as a media group (up to 10 items). Useful for forwarding album photos/videos to Telegram. The service downloads media from Immich and uploads it to Telegram, bypassing any CORS restrictions.
+Send notifications to Telegram. Supports multiple formats:
+
+- **Text message** - When `urls` is empty or not provided
+- **Single photo** - When `urls` contains one photo
+- **Single video** - When `urls` contains one video
+- **Media group** - When `urls` contains multiple items
+
+The service downloads media from Immich and uploads it to Telegram, bypassing any CORS restrictions. Large lists of media are automatically split into multiple media groups based on the `max_group_size` parameter (default: 10 items per group).
+
+**Examples:**
+
+Text message:
 
 ```yaml
-service: immich_album_watcher.send_telegram_media_group
+service: immich_album_watcher.send_telegram_notification
+target:
+  entity_id: sensor.album_name_asset_count
+data:
+  chat_id: "-1001234567890"
+  caption: "Check out the new album!"
+  disable_web_page_preview: true
+```
+
+Single photo:
+
+```yaml
+service: immich_album_watcher.send_telegram_notification
+target:
+  entity_id: sensor.album_name_asset_count
+data:
+  chat_id: "-1001234567890"
+  urls:
+    - url: "https://immich.example.com/api/assets/xxx/thumbnail?key=yyy"
+      type: photo
+  caption: "Beautiful sunset!"
+```
+
+Media group:
+
+```yaml
+service: immich_album_watcher.send_telegram_notification
 target:
   entity_id: sensor.album_name_asset_count
 data:
@@ -131,18 +168,21 @@ data:
     - url: "https://immich.example.com/api/assets/zzz/video/playback?key=yyy"
       type: video
   caption: "New photos from the album!"
-  reply_to_message_id: 123  # optional
+  reply_to_message_id: 123
 ```
 
 | Field | Description | Required |
 |-------|-------------|----------|
 | `chat_id` | Telegram chat ID to send to | Yes |
-| `urls` | List of media items with `url` and `type` (photo/video) | Yes |
+| `urls` | List of media items with `url` and `type` (photo/video). Empty for text message. | No |
 | `bot_token` | Telegram bot token (uses configured token if not provided) | No |
-| `caption` | Caption for the media group (applied to first item) | No |
+| `caption` | For media: caption applied to first item. For text: the message text. | No |
 | `reply_to_message_id` | Message ID to reply to | No |
+| `disable_web_page_preview` | Disable link previews in text messages | No |
+| `max_group_size` | Maximum media items per group (2-10). Large lists split into multiple groups. Default: 10 | No |
+| `chunk_delay` | Delay in milliseconds between sending multiple groups (0-60000). Useful for rate limiting. Default: 0 | No |
 
-The service returns a response with `success` status and `message_ids` of sent messages.
+The service returns a response with `success` status and `message_id` (single message), `message_ids` (media group), or `groups_sent` (number of groups when split).
 
 ## Events