## Why
Unrecognized settings can be silently ignored, leaving typos or deprecated configuration unnoticed.
## What changed
- Collect warnings for unrecognized fields in effective configuration and requirements layers, including unknown feature keys in configuration.
- Report sources and field names without configuration values, show up to three entries, and provide migration hints for `network_proxy`, `allowed_permissions`, and `include_view_image_tool`.
- Emit project-specific warnings when starting a thread and suppress repeated startup warnings in the app server and TUI.
## Testing
Add coverage for merged configuration, disabled layers, startup and project warning delivery, omission of configuration values, and warning deduplication.
GitOrigin-RevId: 464cef87882502b19865ae10b50b6f82defb7296