fix(rlcd): freeze after flash - disable auto-screensaver on monochrome + reduce video stream hog
Frozen screen caused by 2 runtime issues after init fixes 3770ac89:
- BouncingBalls screensaver full_refresh SPI at 10MHz for 300x400 takes ~100ms per frame, hogs LVGL lock -> UI appears frozen stuck on weird image
- MCP video stream task vTaskDelay 5ms streaming holds LVGL lock too often -> starves UI and screenshot (could not acquire LVGL lock)
Fix:
- DisplayIdle tick: for !supportsBacklight (RLCD) don't auto-activate screensaver, only handle wake. Prevents heavy animation entering automatically after timeout (SD may have 60s setting).
- McpSystem video stream: 50ms->100ms idle, 5ms->30ms streaming to release LVGL lock
- Screenshot API: 100ms->500ms lock timeout, task 50->300ms for slow SPI
Build 0x2b79e0 RLCD, flashed.
Co-Authored-By: internal-model
Adolfo Reyna
6f095081d2