Adds Feishu (ByteDance's enterprise messaging platform) as a gateway
platform adapter with full feature parity: WebSocket + webhook transports,
message batching, dedup, rate limiting, rich post/card content parsing,
media handling (images/audio/files/video), group @mention gating,
reaction routing, and interactive card button support.
Cherry-picked from PR #1793 by penwyp with:
- Moved to current main (PR was 458 commits behind)
- Fixed _send_with_retry shadowing BasePlatformAdapter method (renamed to
_feishu_send_with_retry to avoid signature mismatch crash)
- Fixed import structure: aiohttp/websockets imported independently of
lark_oapi so they remain available when SDK is missing
- Fixed get_hermes_home import (hermes_constants, not hermes_cli.config)
- Added skip decorators for tests requiring lark_oapi SDK
- All 16 integration points added surgically to current main
New dependency: lark-oapi>=1.5.3,<2 (optional, pip install hermes-agent[feishu])
Fixes#1788
Co-authored-by: penwyp <penwyp@users.noreply.github.com>