feat: smart video size warnings + Jinja2 template autocomplete

Video size warnings:
- Add file_size field to ImmichAssetInfo from exifInfo.fileSizeInByte
- Expose per-target max_video_size (50 MB for Telegram, none for others)
- Compute has_oversized_videos and per-asset oversized flag in template context
- Default templates show warning only when videos actually exceed the limit
- Templates no longer hardcode Telegram-specific logic

Template autocomplete:
- New jinja-autocomplete.ts engine with contextual completions
- Top-level variables ({{ }}), asset/album fields (dot access in loops),
  Jinja2 filters (|), block tags ({% %}), and loop.* special vars
- JinjaEditor accepts optional variables prop via CodeMirror Compartment
- Wired into template-configs and command-template-configs pages

Also: fix template emoji (📷 → 📎) and sync sample_context with new vars.

frontend/package-lock.json

@@ -8,6 +8,7 @@
 			"name": "notify-bridge-frontend",
 			"version": "0.1.0",
 			"dependencies": {
+				"@codemirror/autocomplete": "^6.18.0",
 				"@codemirror/lang-html": "^6.4.11",
 				"@codemirror/language": "^6.12.2",
 				"@codemirror/state": "^6.6.0",