feat(gateway): add Feishu/Lark platform support (#3817)

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>

hermes_cli/tools_config.py

@@ -140,7 +140,8 @@ PLATFORMS = {
     "homeassistant": {"label": "🏠 Home Assistant", "default_toolset": "hermes-homeassistant"},
     "email":    {"label": "📧 Email",      "default_toolset": "hermes-email"},
     "matrix":   {"label": "💬 Matrix",     "default_toolset": "hermes-matrix"},
-    "dingtalk": {"label": "💬 DingTalk",   "default_toolset": "hermes-dingtalk"},
+ "dingtalk": {"label": "💬 DingTalk", "default_toolset": "hermes-dingtalk"},
+    "feishu": {"label": "🪽 Feishu", "default_toolset": "hermes-feishu"},
     "api_server": {"label": "🌐 API Server", "default_toolset": "hermes-api-server"},
     "mattermost": {"label": "💬 Mattermost", "default_toolset": "hermes-mattermost"},
 }