Add Telegram file ID caching and reverse geocoding fields

Implement caching for Telegram file_ids to avoid re-uploading the same media.
Cached IDs are reused for subsequent sends, improving performance significantly.
Added configurable cache TTL option (1-168 hours, default 48).

Also added city, state, and country fields from Immich reverse geocoding
to asset data in events and get_assets service.

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

README.md

@@ -77,6 +77,7 @@ A Home Assistant custom integration that monitors [Immich](https://immich.app/)
 | Albums | Albums to monitor | Required |
 | Scan Interval | How often to check for changes (seconds) | 60 |
 | Telegram Bot Token | Bot token for sending media to Telegram (optional) | - |
+| Telegram Cache TTL | How long to cache uploaded file IDs (hours, 1-168) | 48 |
 
 ## Entities Created (per album)
 
@@ -241,6 +242,8 @@ Send notifications to Telegram. Supports multiple formats:
 
 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).
 
+**File ID Caching:** When media is uploaded to Telegram, the service caches the returned `file_id`. Subsequent sends of the same media will use the cached `file_id` instead of re-uploading, significantly improving performance. The cache TTL is configurable in hub options (default: 48 hours, range: 1-168 hours). The cache is persistent across Home Assistant restarts and is stored per album.
+
 **Examples:**
 
 Text message:
@@ -420,6 +423,9 @@ Each item in the `added_assets` list contains the following fields:
 | `rating` | User rating of the asset (1-5 stars, or `null` if not rated) |
 | `latitude` | GPS latitude coordinate (or `null` if no geolocation) |
 | `longitude` | GPS longitude coordinate (or `null` if no geolocation) |
+| `city` | City name from reverse geocoding (or `null` if unavailable) |
+| `state` | State/region name from reverse geocoding (or `null` if unavailable) |
+| `country` | Country name from reverse geocoding (or `null` if unavailable) |
 | `url` | Public URL to view the asset (only present if album has a shared link) |
 | `download_url` | Direct download URL for the original file (if shared link exists) |
 | `playback_url` | Video playback URL (for VIDEO assets only, if shared link exists) |