fix: get_instance_name reads nested instance.name from YAML

tests/test_instance_config.py

@@ -10,3 +10,27 @@ class TestInstanceConfig:
         from app.instance_config import get_instance_name
         name = get_instance_name()
         assert isinstance(name, str)
+
+    def test_reads_nested_instance_name(self, tmp_path, monkeypatch):
+        """get_instance_name should read instance.name from YAML, not flat instance_name."""
+        monkeypatch.setenv("DATA_DIR", str(tmp_path))
+        monkeypatch.setenv("TESTING", "1")
+        monkeypatch.setenv("JWT_SECRET_KEY", "test-secret-key-min-32-characters!!")
+
+        state_dir = tmp_path / "state"
+        state_dir.mkdir(exist_ok=True)
+        (state_dir / "instance.yaml").write_text(
+            "instance:\n  name: Acme Analytics\n  subtitle: Data Team\n"
+        )
+
+        import importlib
+        import app.instance_config as mod
+        # Reset cached config to force reload
+        mod._instance_config = None
+        importlib.reload(mod)
+
+        assert mod.get_instance_name() == "Acme Analytics"
+        assert mod.get_instance_subtitle() == "Data Team"
+
+        # Cleanup: reset cache after test
+        mod._instance_config = None