feat(feishu): replace built-in SDK with community plugin

Replace the built-in Feishu SDK with the community-maintained
clawdbot-feishu plugin by @m1heng.

Changes:
- Remove src/feishu/ directory (19 files)
- Remove src/channels/plugins/outbound/feishu.ts
- Remove src/channels/plugins/normalize/feishu.ts
- Remove src/config/types.feishu.ts
- Remove feishu exports from plugin-sdk/index.ts
- Remove FeishuConfig from types.channels.ts

New features in community plugin:
- Document tools (read/create/edit Feishu docs)
- Wiki tools (navigate/manage knowledge base)
- Drive tools (folder/file management)
- Bitable tools (read/write table records)
- Permission tools (collaborator management)
- Emoji reactions support
- Typing indicators
- Rich media support (bidirectional image/file transfer)
- @mention handling
- Skills for feishu-doc, feishu-wiki, feishu-drive, feishu-perm

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

extensions/feishu/openclaw.plugin.json

@@ -1,6 +1,7 @@
 {
   "id": "feishu",
   "channels": ["feishu"],
+  "skills": ["./skills"],
   "configSchema": {
     "type": "object",
     "additionalProperties": false,