feat: display messages as terminal output

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

tests/test_store.py

@@ -41,5 +41,21 @@ 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] == "2"
+    ).fetchone()[0] == "3"
+    assert "displayed_at" in {
+        row["name"] for row in store.db.execute("PRAGMA table_info(messages)")
+    }
+
+
+def test_mark_displayed_releases_lease_without_acknowledging(tmp_path):
+    store = Store(tmp_path / "queue.sqlite3")
+    message_id = store.add("a", "b", "hello")
+    lease_id = store.claim(message_id, "endpoint")
+    assert lease_id is not None
+
+    assert store.mark_displayed(message_id, lease_id) is True
+    row = store.list()[0]
+    assert row["state"] == "pending"
+    assert row["displayed_at"] is not None
+    assert store.db.execute("SELECT COUNT(*) FROM leases").fetchone()[0] == 0
     store.close()