Implement automatic reminder engine with admin and company UI.

Add schema v6, read-only scan rules for unsubmitted flows, gaps and pending reviews, deduplicated delivery with append-only event history, daily scan thread, and full API/frontend integration with 18 new tests.

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

tests/test_persistence.py

@@ -41,7 +41,7 @@ class PersistenceTestCase(unittest.TestCase):
 class MigrationTests(PersistenceTestCase):
     def test_migrate_creates_schema_and_is_idempotent(self) -> None:
         first = applied_versions(self.connection)
-        self.assertEqual([1, 2, 3, 4, 5], first)
+        self.assertEqual([1, 2, 3, 4, 5, 6], first)
         self.assertEqual([], migrate(self.connection))
         self.assertEqual(first, applied_versions(self.connection))
         tables = {
@@ -73,19 +73,22 @@ class MigrationTests(PersistenceTestCase):
             "transfer_match_candidates",
             "current_transfer_decisions",
             "transfer_observation_claims",
+            "reminder_settings",
+            "reminders",
+            "reminder_events",
             "schema_migrations",
         ):
             self.assertIn(table, tables)
 
     def test_rollback_removes_schema_and_forward_rebuilds_it(self) -> None:
-        self.assertEqual([5, 4, 3, 2, 1], rollback(self.connection, 0))
+        self.assertEqual([6, 5, 4, 3, 2, 1], rollback(self.connection, 0))
         self.assertEqual([], applied_versions(self.connection))
         remaining = self.connection.execute(
             "SELECT name FROM sqlite_master WHERE type = 'table' AND name = 'source_rows'"
         ).fetchone()
         self.assertIsNone(remaining)
-        self.assertEqual([1, 2, 3, 4, 5], migrate(self.connection))
-        self.assertEqual([1, 2, 3, 4, 5], applied_versions(self.connection))
+        self.assertEqual([1, 2, 3, 4, 5, 6], migrate(self.connection))
+        self.assertEqual([1, 2, 3, 4, 5, 6], applied_versions(self.connection))
 
     def test_rollback_to_4_keeps_bank_evidence_and_drops_event_layer(self) -> None:
         self.import_sample()
@@ -93,7 +96,7 @@ class MigrationTests(PersistenceTestCase):
             "SELECT COUNT(*) AS n FROM source_rows"
         ).fetchone()["n"]
         self.assertGreater(row_count, 0)
-        self.assertEqual([5], rollback(self.connection, 4))
+        self.assertEqual([6, 5], rollback(self.connection, 4))
         # The pre-migration evidence and schema are untouched.
         self.assertEqual(
             row_count,