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

src/api_key_manager.py

@@ -48,8 +48,18 @@ class APIKeyManager:
         """Load and decrypt API keys"""
         if not os.path.exists(self.api_keys_file):
             return {}
-        with open(self.api_keys_file, 'r', encoding="utf-8") as f:
-            encrypted_keys = json.load(f)
+        try:
+            with open(self.api_keys_file, 'r', encoding="utf-8") as f:
+                encrypted_keys = json.load(f)
+        except (json.JSONDecodeError, OSError) as e:
+            # A corrupt/truncated api_keys.json must not crash load() (called on
+            # startup via app_initializer) — treat it as no stored keys.
+            logger.warning("Failed to read API keys file: %s", e)
+            return {}
+        if not isinstance(encrypted_keys, dict):
+            # Legacy/wrong shape (e.g. a list) — .items() would raise. Ignore it.
+            logger.warning("API keys file has unexpected shape (%s); ignoring", type(encrypted_keys).__name__)
+            return {}
 
         decrypted = {}
         for provider, key in encrypted_keys.items():