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>

src/plugin-sdk/index.ts

@@ -370,22 +370,5 @@ export {
 } from "../line/markdown-to-line.js";
 export type { ProcessedLineMessage } from "../line/markdown-to-line.js";
 
-// Channel: Feishu
-export {
-  listFeishuAccountIds,
-  resolveDefaultFeishuAccountId,
-  resolveFeishuAccount,
-  type ResolvedFeishuAccount,
-} from "../feishu/accounts.js";
-export {
-  resolveFeishuConfig,
-  resolveFeishuGroupEnabled,
-  resolveFeishuGroupRequireMention,
-} from "../feishu/config.js";
-export { feishuOutbound } from "../channels/plugins/outbound/feishu.js";
-export { normalizeFeishuTarget } from "../channels/plugins/normalize/feishu.js";
-export { probeFeishu, type FeishuProbe } from "../feishu/probe.js";
-export { monitorFeishuProvider } from "../feishu/monitor.js";
-
 // Media utilities
 export { loadWebMedia, type WebMediaResult } from "../web/media.js";