feat: complete reliable coordination adapter

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

tests/test_retry.py

@@ -0,0 +1,27 @@
+from tamq.cli import main
+from tamq.store import Store
+
+
+def test_retry_cli_resets_only_terminal_failures(tmp_path, monkeypatch, capsys):
+    state = tmp_path / "state"
+    monkeypatch.setenv("TAMQ_STATE_DIR", str(state))
+    store = Store(state / "tamq.sqlite3")
+    failed = store.add("a", "b", "failed")
+    pending = store.add("a", "b", "pending")
+    store.db.execute(
+        "UPDATE messages SET state='failed',attempt_count=4,last_failure_reason='OSError' "
+        "WHERE message_id=?",
+        (failed,),
+    )
+    store.db.commit()
+    store.close()
+
+    assert main(["retry", failed]) == 0
+    assert capsys.readouterr().out.strip() == failed
+    reopened = Store(state / "tamq.sqlite3")
+    assert reopened.message(failed)["state"] == "pending"
+    assert reopened.message(failed)["attempt_count"] == 0
+    reopened.close()
+
+    assert main(["retry", pending]) == 1
+    assert "not failed" in capsys.readouterr().err