#8479: feat(telegram): extract animation/GIF metadata & support animated/video stickers

## Summary Two improvements to Telegram media handling for better agent context: ### 1. Animation/GIF metadata extraction When users send GIFs/animations via Telegram, agents previously received a UUID-based filename (e.g. `file_12---48317467-8e25-4ba9-8b89-56230dbc3e05.mp4`) with no semantic context. This extracts Telegram's native animation metadata (especially `file_name`, which often contains search terms like `thumbs-up.mp4`, `like-awesome.mp4`) and passes it through to the agent context. ### 2. Animated/video sticker passthrough Previously, animated (TGS) and video (WEBM) stickers were **silently dropped** — `resolveMedia()` returned null, and the entire message was skipped. This is a significant UX issue since most modern Telegram stickers are animated. Now, animated/video stickers return a metadata-only result (no media download) containing emoji + setName, formatted as `[Sticker 😘 from "UtyaDuck"]` so agents can understand the sticker's intent. ## Changes **Animation/GIF metadata:** - `src/telegram/bot/types.ts` — New `AnimationMetadata` interface - `src/telegram/bot/delivery.ts` — Handle `msg.animation` separately in `resolveMedia()` - `src/telegram/bot-message-context.ts` — Format GIF placeholder as `<media:gif "filename">` - `src/telegram/bot-handlers.ts` — Pass `animationMetadata` through handler pipelines **Animated/video sticker support:** - `src/telegram/bot/delivery.ts` — Return metadata-only for animated/video stickers instead of null - `src/telegram/bot-handlers.ts` — Don't skip sticker messages that have metadata resolved - `src/telegram/bot-message-context.ts` — Format metadata-only stickers with emoji/setName context ## Before/After **GIF:** | | Before | After | |---|---|---| | Agent sees | `file_12---uuid.mp4` | `<media:gif "thumbs-up.mp4">` | | Understanding | Requires ffmpeg + vision model | Instant from file_name | **Animated Sticker:** | | Before | After | |---|---|---| | Agent sees | *(nothing — message dropped)* | `[Sticker 😘 from "UtyaDuck"]` | | Understanding | Impossible | Instant from emoji + set context | ## Testing Tested in production with various media types: - Telegram inline GIF search → file_name contains search terms ✅ - Forwarded GIFs → file_name preserved ✅ - Animated stickers (TGS) → emoji + setName passed through ✅ - Video stickers (WEBM) → emoji + setName passed through ✅ - Static stickers → unaffected (existing code path) ✅