API keys: skip undecryptable entries on load

APIKeyManager.load() decrypts every stored key with a dict comprehension
and no error handling. If the .key file no longer matches the ciphertext in
api_keys.json — key rotated, a partial/!mismatched data restore, or a
corrupted .key — Fernet.decrypt raises cryptography.fernet.InvalidToken.

app_initializer.py calls api_key_manager.load() during startup, so a single
undecryptable entry takes down the whole app at boot, and the user can't
reach the UI to fix it.

Decrypt each key in a loop and, on InvalidToken/ValueError, log a warning
and skip that one entry while still returning every key that decrypts
cleanly. One bad/stale key no longer blocks startup.

tests/test_api_key_manager_resilience.py saves a valid key, then injects an
entry encrypted under a different Fernet key (InvalidToken) and a malformed
token (ValueError), and asserts load() returns the good key and skips the
bad ones without raising. Fails before this change.

src/api_key_manager.py

@@ -1,7 +1,10 @@
 import os
 import json
+import logging
 from typing import Dict
-from cryptography.fernet import Fernet
+from cryptography.fernet import Fernet, InvalidToken
+
+logger = logging.getLogger(__name__)
 
 class APIKeyManager:
     def __init__(self, data_dir: str):
@@ -47,8 +50,12 @@ class APIKeyManager:
             return {}
         with open(self.api_keys_file, 'r', encoding="utf-8") as f:
             encrypted_keys = json.load(f)
-        return {
-            provider: self.decrypt_api_key(key)
-            for provider, key in encrypted_keys.items()
-        }
+
+        decrypted = {}
+        for provider, key in encrypted_keys.items():
+            try:
+                decrypted[provider] = self.decrypt_api_key(key)
+            except (InvalidToken, ValueError) as e:
+                logger.warning("Failed to decrypt API key for %s: %s", provider, e)
+        return decrypted
 

tests/test_api_key_manager_resilience.py

@@ -0,0 +1,35 @@
+import os
+import json
+from src.api_key_manager import APIKeyManager
+from cryptography.fernet import Fernet
+
+def test_api_key_manager_load_resilience(tmp_path):
+    mgr = APIKeyManager(str(tmp_path))
+    
+    # Save a valid key
+    mgr.save("good_provider", "good_value")
+    
+    # Create another key manager/Fernet instance with a different key to produce an undecryptable token
+    other_key = Fernet.generate_key()
+    other_f = Fernet(other_key)
+    undecryptable_token = other_f.encrypt(b"bad_value").decode()
+    
+    # Manually edit api_keys.json to include the undecryptable token
+    with open(mgr.api_keys_file, "r", encoding="utf-8") as f:
+        keys = json.load(f)
+    
+    keys["bad_provider"] = undecryptable_token
+    # Also add a malformed/garbage token (causes ValueError/binascii.Error)
+    keys["garbage_provider"] = "not-a-valid-base64-fernet-token"
+    
+    with open(mgr.api_keys_file, "w", encoding="utf-8") as f:
+        json.dump(keys, f)
+        
+    # Load keys
+    loaded = mgr.load()
+    
+    # Assert load() returns the still-decryptable key and skips the bad ones without raising
+    assert "good_provider" in loaded
+    assert loaded["good_provider"] == "good_value"
+    assert "bad_provider" not in loaded
+    assert "garbage_provider" not in loaded