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/aminer-deep-search/commands/aminer-deep-search.md

@@ -0,0 +1,51 @@
+---
+description: AMiner deep multi-round paper collection for survey references
+argument-hint: "[research topic | topic: ... target-size: 400 max-rounds: 12]"
+allowed-tools: Read, Bash, Glob, Grep
+---
+
+# /aminer-deep-search - AMiner Deep Search
+
+User invoked the AMiner deep paper collection skill with the following arguments:
+
+```text
+$ARGUMENTS
+```
+
+## Your task
+
+Follow `${CLAUDE_PLUGIN_ROOT}/SKILL.md`. You are the controller: run the tool scripts, read their JSON output, judge relevance yourself, and iterate. There is no external LLM mode and nothing to configure beyond `AMINER_API_KEY`.
+
+Use this command only for deep survey-style paper collection, not for simple paper lookup or lightweight recommendations.
+
+### 1. Parse `$ARGUMENTS`
+
+- `topic`: required research topic. Preserve the user's wording. If absent or too vague, ask for a concrete topic.
+- `target-size`: optional final paper target, default 400.
+- `max-rounds`: optional round budget, default 12.
+
+### 2. Pre-flight
+
+```bash
+[ -z "${AMINER_API_KEY:-}" ] && echo "AMINER_API_KEY missing" || echo "AMINER_API_KEY exists"
+```
+
+If missing, stop and tell the user to set `AMINER_API_KEY`. Never print the key. The scripts are pure stdlib — no dependency installation is needed.
+
+### 3. Run the round protocol
+
+Execute the Round Protocol from `${CLAUDE_PLUGIN_ROOT}/SKILL.md`:
+
+- Round 0: derive 4–8 seed queries, estimate cost; confirm with the user if the estimate is ≥¥5.
+- Each round (max `max-rounds`): search via
+  `python3 "${CLAUDE_PLUGIN_ROOT}/scripts/aminer_api.py" search --query "..." --order n_citation`,
+  filter results for relevance yourself, add the kept items via
+  `python3 "${CLAUDE_PLUGIN_ROOT}/scripts/paper_set.py" add`,
+  snowball with `references --ids ...` on ≤5 strong unexpanded seeds, and check `stats`.
+- Stop when `target-size` is reached, results are exhausted, or 2 consecutive rounds add <5 papers.
+
+Keep the state file and exports under the current working directory (`outputs/`).
+
+### 4. Present the result
+
+Run `export` and report the final paper count, the total cost (sum of `[cost]` stderr lines), and the output path. If the run fails due to missing configuration or API errors, show the actionable error without exposing secrets. Never fabricate papers.