API key come hash SHA-256, una per sessione, TTL rinnovabile (#41)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/backend/tests/test_migrations.py

@@ -107,3 +107,27 @@ class TestBaseMigrationNoopsOnExistingSchema:
         assert "image_path" in {
             c["name"] for c in insp.get_columns("recipes")
         }
+
+
+class TestApiKeyHashMigration:
+    """015_api_key_hash: users.api_key -> api_keys table, and back (#41)."""
+
+    def test_015_upgrade_and_downgrade(self, sqlite_database_url):
+        db_path, _ = sqlite_database_url
+        cfg = _alembic_config()
+        command.upgrade(cfg, "head")
+
+        insp = _inspect(db_path)
+        assert "api_keys" in insp.get_table_names()
+        assert "api_key" not in {c["name"] for c in insp.get_columns("users")}
+        assert {c["name"] for c in insp.get_columns("api_keys")} >= {
+            "user_id", "key_hash", "created_at", "expires_at", "last_used_at",
+        }
+
+        command.downgrade(cfg, "014_vision_fk_ondelete")
+        insp = _inspect(db_path)
+        assert "api_keys" not in insp.get_table_names()
+        assert "api_key" in {c["name"] for c in insp.get_columns("users")}
+
+        command.upgrade(cfg, "head")  # and up again
+        assert "api_keys" in _inspect(db_path).get_table_names()