Add {year} variable to asset templates in Immich Album Watcher

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Common/Immich Album Watcher/README.md

@@ -107,6 +107,7 @@ These variables can be used in the image and video asset templates. Also used fo
 | `{type}` | Asset type (IMAGE or VIDEO) |
 | `{created}` | Creation date/time (always shown) |
 | `{created_if_unique}` | Creation date/time formatted with template if dates differ, empty if all same |
+| `{year}` | Year the asset was created (4-digit, e.g., 2024) |
 | `{owner}` | Owner display name |
 | `{url}` | Public URL to view the asset (empty if no shared link) |
 | `{download_url}` | Direct download URL for the original file |