fix(api): hide sensitive fields by default

Add model-level hidden fields for secrets, tokens, keys, notification
credentials, deployment logs, and environment values. Allow explicit
read:sensitive API access to reveal gated private keys and deployment logs,
and cover the behavior with feature and unit tests.

app/Http/Controllers/Api/SecurityController.php

@@ -16,6 +16,10 @@ class SecurityController extends Controller
             $team->makeHidden([
                 'private_key',
             ]);
+        } else {
+            $team->makeVisible([
+                'private_key',
+            ]);
         }
 
         return serializeApiResponse($team);