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/tests/test_paper_set.py

@@ -0,0 +1,109 @@
+from __future__ import annotations
+
+import contextlib
+import importlib.util
+import io
+import json
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+from unittest import mock
+
+
+SKILL_DIR = Path(__file__).resolve().parents[1]
+MODULE_PATH = SKILL_DIR / "scripts" / "paper_set.py"
+SPEC = importlib.util.spec_from_file_location("aminer_deep_search_paper_set", MODULE_PATH)
+assert SPEC and SPEC.loader
+paper_set = importlib.util.module_from_spec(SPEC)
+sys.modules[SPEC.name] = paper_set
+SPEC.loader.exec_module(paper_set)
+
+
+def run_main(argv, stdin_text=None):
+    stdout = io.StringIO()
+    with contextlib.redirect_stdout(stdout):
+        if stdin_text is not None:
+            with mock.patch.object(sys, "stdin", io.StringIO(stdin_text)):
+                code = paper_set.main(argv)
+        else:
+            code = paper_set.main(argv)
+    return code, stdout.getvalue()
+
+
+class PaperSetTests(unittest.TestCase):
+    def setUp(self):
+        self.tmp = tempfile.TemporaryDirectory()
+        self.state = str(Path(self.tmp.name) / "paper_set.json")
+
+    def tearDown(self):
+        self.tmp.cleanup()
+
+    def test_add_from_stdin_dedupes_and_counts(self):
+        items = [
+            {"id": "a", "title": "Paper A", "year": 2020},
+            {"id": "b", "title": "Paper B"},
+        ]
+        code, out = run_main(["--file", self.state, "add"], json.dumps(items))
+        self.assertEqual(code, 0)
+        self.assertEqual(json.loads(out), {"added": 2, "duplicates": 0, "total": 2})
+
+        again = [{"id": "a", "title": "Paper A"}, {"id": "c", "title": "Paper C"}]
+        code, out = run_main(["--file", self.state, "add"], json.dumps(again))
+        self.assertEqual(json.loads(out), {"added": 1, "duplicates": 1, "total": 3})
+
+    def test_add_bare_ids(self):
+        code, out = run_main(["--file", self.state, "add", "--ids", "x", "y", "x"])
+        self.assertEqual(code, 0)
+        self.assertEqual(json.loads(out), {"added": 2, "duplicates": 1, "total": 2})
+
+    def test_source_paper_ids_mark_seeds_expanded(self):
+        items = [{"id": "a", "title": "A", "source_paper_ids": ["seed1", "seed2"]}]
+        run_main(["--file", self.state, "add"], json.dumps(items))
+        code, out = run_main(["--file", self.state, "stats"])
+        stats = json.loads(out)
+        self.assertEqual(stats["expanded_seeds"], ["seed1", "seed2"])
+        # source_paper_ids must not be persisted onto the paper entry
+        state = json.loads(Path(self.state).read_text(encoding="utf-8"))
+        self.assertNotIn("source_paper_ids", state["papers"]["a"])
+
+    def test_mark_expanded(self):
+        run_main(["--file", self.state, "mark-expanded", "--ids", "s1"])
+        code, out = run_main(["--file", self.state, "stats"])
+        self.assertEqual(json.loads(out)["expanded_seeds"], ["s1"])
+
+    def test_stats_by_year(self):
+        items = [
+            {"id": "a", "title": "A", "year": 2021},
+            {"id": "b", "title": "B", "year": 2021},
+            {"id": "c", "title": "C"},
+        ]
+        run_main(["--file", self.state, "add"], json.dumps(items))
+        _, out = run_main(["--file", self.state, "stats"])
+        stats = json.loads(out)
+        self.assertEqual(stats["total"], 3)
+        self.assertEqual(stats["by_year"]["2021"], 2)
+        self.assertEqual(stats["by_year"]["unknown"], 1)
+
+    def test_export_shape_and_file(self):
+        items = [
+            {"id": "a", "title": "Paper A", "year": 2020, "venue": "V"},
+            {"id": "no-title"},
+        ]
+        run_main(["--file", self.state, "add"], json.dumps(items))
+        out_path = str(Path(self.tmp.name) / "final.json")
+        code, out = run_main(["--file", self.state, "export", "-o", out_path])
+        self.assertEqual(code, 0)
+        result = json.loads(out)
+        self.assertEqual(result, {"count": 1, "path": out_path})
+        exported = json.loads(Path(out_path).read_text(encoding="utf-8"))
+        self.assertEqual(exported, [{"id": "a", "title": "Paper A"}])
+
+    def test_empty_stdin_is_a_structured_error(self):
+        code, out = run_main(["--file", self.state, "add"], "")
+        self.assertEqual(code, 2)
+        self.assertEqual(json.loads(out)["error"], "invalid_input")
+
+
+if __name__ == "__main__":
+    unittest.main()