Simplify home view and drop motion detection

- Top nav tabs (Home/Media/Cameras/Settings) replace the right-side button cluster
- Home view now shows calendar 90% / todo 10% vertically; lights, locks,
  alarm, thermostats removed from the dashboard since the photo frame now
  owns the idle space and the nav covers the remaining sections
- Motion detection deleted: the go2rtc-based Kitchen_Panel poll was only
  there to wake the screen before idle timeout, which photo-frame exit on
  touch replaces

src/hooks/useIdle.ts

@@ -1,14 +1,9 @@
 import { useEffect } from 'react';
 import { useUIStore } from '@/stores/uiStore';
 
-type ElectronAPILike = {
-  motion?: { onDetected: (cb: () => void) => () => void };
-};
-
 /**
  * Tracks touch/mouse/keyboard activity. After `timeoutMs` of no activity,
  * flips the UI into idle mode (photo frame). Any activity exits idle.
- * Motion detected by Electron's MotionDetector also cancels idle.
  */
 export function useIdle(timeoutMs: number) {
   const isIdle = useUIStore((s) => s.isIdle);
@@ -34,15 +29,11 @@ export function useIdle(timeoutMs: number) {
     ];
     for (const e of events) document.addEventListener(e, reset, { passive: true });
 
-    const api = (window as unknown as { electronAPI?: ElectronAPILike }).electronAPI;
-    const unsubMotion = api?.motion?.onDetected?.(() => reset());
-
     reset();
 
     return () => {
       if (timer) clearTimeout(timer);
       for (const e of events) document.removeEventListener(e, reset);
-      if (unsubMotion) unsubMotion();
     };
   }, [timeoutMs, setIdle]);