feat: IMAP mail sync with thread-to-contact matching (PRD §6.1)

Real IMAP connection via imapflow library:
- Connects to IMAP server (IMAPFlow, TLS on port 993)
- Fetches recent messages (configurable limit, default 20)
- Extracts: from, fromEmail, subject, date, snippet (200 chars)
- Thread-to-contact matching (PRD §6.1):
  1. Match sender email against persons table
  2. If no person match, extract domain and match against company.website
  3. Returns matchedCompany + matchedPerson for each email
- Audit-logged (action: crm.mailsync:imap)
- Zod validated (host, port, user, password, folder, limit)
- 502 on IMAP connection failure with detail
- 400 on validation failure

Tested: invalid creds → 502 'IMAP connection failed', missing host → 400

skills/multi-search-engine/SKILL.md

@@ -0,0 +1,78 @@
+---
+name: "multi-search-engine"
+description: "Multi search engine integration with 8 domestic (CN) search engines. Supports advanced search operators, time filters, site search, and WeChat article search. No API keys required."
+---
+
+# Multi Search Engine v2.0.1
+
+Integration of 8 domestic Chinese search engines for web crawling without API keys.
+
+## Search Engines (Domestic - CN Only)
+
+- **Baidu**: `https://www.baidu.com/s?wd={keyword}`
+- **Bing CN**: `https://cn.bing.com/search?q={keyword}&ensearch=0`
+- **Bing INT**: `https://cn.bing.com/search?q={keyword}&ensearch=1`
+- **360**: `https://www.so.com/s?q={keyword}`
+- **Sogou**: `https://sogou.com/web?query={keyword}`
+- **WeChat**: `https://wx.sogou.com/weixin?type=2&query={keyword}`
+- **Toutiao**: `https://so.toutiao.com/search?keyword={keyword}`
+- **Jisilu**: `https://www.jisilu.cn/explore/?keyword={keyword}`
+
+## Quick Examples
+
+```javascript
+// Basic search (Baidu)
+web_fetch({"url": "https://www.baidu.com/s?wd=python+tutorial"})
+
+// Site-specific (Bing CN)
+web_fetch({"url": "https://cn.bing.com/search?q=site:github.com+react&ensearch=0"})
+
+// File type (Baidu)
+web_fetch({"url": "https://www.baidu.com/s?wd=machine+learning+filetype:pdf"})
+
+// WeChat article search
+web_fetch({"url": "https://wx.sogou.com/weixin?type=2&query=人工智能+最新进展"})
+
+// Toutiao search
+web_fetch({"url": "https://so.toutiao.com/search?keyword=新能源+政策"})
+
+// Jisilu financial data
+web_fetch({"url": "https://www.jisilu.cn/explore/?keyword=REITs"})
+```
+
+## Advanced Operators
+
+| Operator | Example | Description |
+|----------|---------|-------------|
+| `site:` | `site:github.com python` | Search within site |
+| `filetype:` | `filetype:pdf report` | Specific file type |
+| `""` | `"machine learning"` | Exact match |
+| `-` | `python -snake` | Exclude term |
+| `OR` | `cat OR dog` | Either term |
+
+## Time Filters
+
+| Parameter | Description |
+|-----------|-------------|
+| `tbs=qdr:h` | Past hour |
+| `tbs=qdr:d` | Past day |
+| `tbs=qdr:w` | Past week |
+| `tbs=qdr:m` | Past month |
+| `tbs=qdr:y` | Past year |
+
+## Search Engine Notes
+
+- **WeChat Search**: Best for searching WeChat public articles and content
+- **Toutiao**: Good for trending topics and news aggregation
+- **Jisilu**: Focused on financial and investment data
+- **Bing INT**: International search results via Bing interface
+- **Bing CN**: Localized Chinese search results
+
+## Documentation
+
+- `references/international-search.md` - Archived international search guide (for reference)
+- `CHANGELOG.md` - Version history
+
+## License
+
+MIT