style: restore PEP8 blank-line separation after dead-code removal

The deletions in the salvaged commit left some top-level defs/classes
separated by a single blank line. Restore the 2-blank-line separation.

agent/anthropic_adapter.py

@@ -892,6 +892,8 @@ def read_claude_code_credentials() -> Optional[Dict[str, Any]]:
             logger.debug("Failed to read ~/.claude/.credentials.json: %s", e)
 
     return None
+
+
 def is_claude_code_token_valid(creds: Dict[str, Any]) -> bool:
     """Check if Claude Code credentials have a non-expired access token."""
     import time

agent/browser_registry.py

@@ -184,6 +184,8 @@ def _resolve(configured: Optional[str]) -> Optional[BrowserProvider]:
             return provider
 
     return None
+
+
 def _reset_for_tests() -> None:
     """Clear the registry. **Test-only.**"""
     with _lock: