fix: support text channel for summary reply and fix root_message_id extraction

[Joe-rq]

Bug Fixes\n\n### 1. Fix root_message_id extraction\nThe original code used incorrect path to extract root_message_id from response_meta.\n\nBefore:\npython\nroot_message_id = ((response_meta or {}).get("data") or {}).get("root_id")\n\n\nAfter:\npython\nroot_message_id = ((response_meta or {}).get("data") or {}).get("root_id") or ((response_meta or {}).get("data") or {}).get("message_id")\n\n\n### 2. Support configurable msg_type for summary reply\nThe original code hardcoded msg_type as "post" for summary reply, ignoring the template configuration.\n\nChanges:\n- Added support for channel: "text" in summary_reply config\n- Added build_summary_text() function for generating text format content\n- Falls back to "post" type if not specified\n\n### 3. New build_summary_text() function\nGenerates plain text format for reply messages:\n- Supports @ mentions\n- Formatted bullet points\n- Optional footer\n\n## Testing\n- [x] Tested with text channel config\n- [x] Verified root_message_id extraction works correctly\n- [x] Both main message and summary reply sent successfully

[github-actions]

自动审查结果

❌ 自动审查发现需要修复的问题。

AI 审查服务暂时不可用，且本次 PR 超出低风险自动放行范围，已要求人工复核。

• [medium] src/openclaw_feishu_cron_kit/core.py, src/openclaw_feishu_cron_kit/renderer.py 需要人工复核: AI 审查服务不可用（502 Server Error: Bad Gateway for url: https://aicode.cat/v1/responses），且本次改动文件或变更规模超出低风险自动合并白名单。

[github-actions]

自动审查结果

❌ 自动审查发现需要修复的问题。

AI 审查服务暂时不可用，且本次 PR 超出低风险自动放行范围，已要求人工复核。

• [medium] src/openclaw_feishu_cron_kit/core.py, src/openclaw_feishu_cron_kit/renderer.py 需要人工复核: AI 审查服务不可用（HTTPSConnectionPool(host='aicode.cat', port=443): Max retries exceeded with url: /v1/responses (Caused by ConnectTimeoutError(<HTTPSConnection(host='aicode.cat', port=443) at 0x7fa0c24b9250>, 'Connection to aicode.cat timed out. (connect timeout=180)'))），且本次改动文件或变更规模超出低风险自动合并白名单。