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/CHANGELOG.md

@@ -0,0 +1,15 @@
+# Changelog
+
+## v2.0.1 (2026-02-06)
+- Simplified documentation
+- Removed gov-related content
+- Optimized for ClawHub publishing
+
+## v2.0.0 (2026-02-06)
+- Added 9 international search engines
+- Enhanced advanced search capabilities
+- Added DuckDuckGo Bangs support
+- Added WolframAlpha knowledge queries
+
+## v1.0.0 (2026-02-04)
+- Initial release with 8 domestic search engines