- Add protocol field (ddp/http) to storage, API schemas, routes, processor
- WledTargetProcessor passes protocol to create_led_client(use_ddp=...)
- Target editor: protocol dropdown + keepalive in collapsible Specific Settings
- FPS, brightness threshold, adaptive FPS moved to main form area
- Hide Specific Settings section for serial devices (protocol is WLED-only)
- Card badge: show DDP/HTTP for WLED devices, Serial for serial devices
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>