Replaced all inline error messages with the standardized `api_error` helper for consistent error response formatting. This improves clarity, maintainability, and ensures uniform error structures across the application. Updated logging for collector failures to include error class and switched to warning level for target unreachable scenarios.
This commit introduces optional `first_name` and `last_name` fields to the user model, including database migrations, backend, and frontend support. It enhances user profiles, updates user creation and editing flows, and refines the UI to display full names where available.
