fix: APIKeyManager.load crashes app startup on a corrupt/wrong-shape api_keys.json (#1565)

tests/test_api_key_manager_corrupt_load.py

@@ -0,0 +1,32 @@
+"""Regression: APIKeyManager.load() must not crash on a corrupt/wrong-shape file.
+
+load() is called during startup (app_initializer). It had no try/except around
+`json.load` and called `encrypted_keys.items()` directly, so a corrupt/truncated
+api_keys.json raised JSONDecodeError and a legacy list-shaped file raised
+AttributeError — both crashing app startup. It now returns {} instead.
+"""
+from src.api_key_manager import APIKeyManager
+
+
+def _mgr(tmp_path):
+    return APIKeyManager(str(tmp_path))
+
+
+def test_corrupt_json_returns_empty(tmp_path):
+    (tmp_path / "api_keys.json").write_text("{not valid json", encoding="utf-8")
+    assert _mgr(tmp_path).load() == {}
+
+
+def test_list_shape_returns_empty(tmp_path):
+    (tmp_path / "api_keys.json").write_text('["openai", "anthropic"]', encoding="utf-8")
+    assert _mgr(tmp_path).load() == {}
+
+
+def test_missing_file_returns_empty(tmp_path):
+    assert _mgr(tmp_path).load() == {}
+
+
+def test_valid_roundtrip(tmp_path):
+    mgr = _mgr(tmp_path)
+    mgr.save("openai", "sk-secret")
+    assert mgr.load() == {"openai": "sk-secret"}