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/coding-agent/verification.md

@@ -0,0 +1,39 @@
+# Verification Reference
+
+Consult when verifying implementations visually or with tests.
+
+## Screenshots
+- Wait for full page load (no spinners)
+- Review yourself before sending
+- Split long pages into 3-5 sections (~800px each)
+- Caption each: "Hero", "Features", "Footer"
+
+## Before Sending
+```
+[ ] Content loaded
+[ ] Shows the specific change
+[ ] No visual bugs
+[ ] Caption explains what user sees
+```
+
+## Fix-Before-Send
+If screenshot shows problem:
+1. Fix code
+2. Re-deploy
+3. New screenshot
+4. Still broken? -> back to 1
+5. Fixed? -> now send
+
+Never send "I noticed X is wrong, will fix" - fix first.
+
+## No UI? Show Output
+
+When verifying API endpoints, show actual output:
+```
+GET /api/users -> {"id": 1, "name": "test"}
+```
+
+Include actual response, not just "it works".
+
+## Flows
+Number sequential states: "1/4: Form", "2/4: Loading", "3/4: Error", "4/4: Success"