feat: complete reliable coordination adapter

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a03397-4d51-7fd1-8ff2-946eb22ea2bc

tests/test_store.py

@@ -41,10 +41,58 @@ def test_store_migrates_legacy_endpoint_rows_to_manual_delivery(tmp_path):
     assert store.endpoints()[0]["delivery_mode"] == "manual"
     assert store.db.execute(
         "SELECT value FROM metadata WHERE key='schema_version'"
-    ).fetchone()[0] == "4"
+    ).fetchone()[0] == "6"
     assert "displayed_at" in {
         row["name"] for row in store.db.execute("PRAGMA table_info(messages)")
     }
+    assert store.db.execute(
+        "SELECT COUNT(*) FROM protocol_events"
+    ).fetchone()[0] == 0
+
+
+def test_protocol_ledger_is_atomic_and_not_duplicated_on_reopen(tmp_path):
+    path = tmp_path / "queue.sqlite3"
+    store = Store(path)
+    message_id = store.add(
+        "source", "target", "first\nsecond", provenance="worker_output"
+    )
+    event = store.protocol_events(message_id=message_id)[0]
+    assert event["event_type"] == "message.accepted"
+    assert event["repo"] == "source"
+    assert event["peer_repo"] == "target"
+    assert json.loads(event["detail"]) == {"line_count": 2}
+    store.close()
+
+    reopened = Store(path)
+    assert len(reopened.protocol_events(message_id=message_id)) == 1
+    reopened.close()
+
+
+def test_schema_v5_backfills_existing_message_lifecycle(tmp_path):
+    path = tmp_path / "legacy-messages.sqlite3"
+    store = Store(path)
+    message_id = store.add("a", "b", "old")
+    store.db.execute("DELETE FROM protocol_events")
+    store.db.execute(
+        "UPDATE messages SET displayed_at=2,injected_at=3,acknowledged_at=4 "
+        "WHERE message_id=?",
+        (message_id,),
+    )
+    store.db.commit()
+    store.close()
+
+    migrated = Store(path)
+    assert [row["event_type"] for row in migrated.protocol_events()] == [
+        "delivery.displayed",
+        "delivery.injected",
+        "message.acknowledged",
+        "message.accepted",
+    ]
+    assert all(
+        json.loads(row["detail"])["backfilled"] is True
+        for row in migrated.protocol_events()
+    )
+    migrated.close()
 
 
 def test_mark_displayed_releases_lease_without_acknowledging(tmp_path):