fix(app): fix sidebar crash when switching iOS theme

Unistyles' StyleSheet.create((theme) => ...) wraps styled components in
<UnistylesComponent> and patches native view properties via C++. When
these dynamic styles are applied to Reanimated's Animated.View, a theme
change causes both systems to fight over the same native node, crashing
with "Unable to find node on an unmounted component."

Fix: use plain React Native StyleSheet for static positioning on
Animated.View, and pass theme-dependent values (backgroundColor) as
inline styles from useUnistyles() instead of Unistyles dynamic sheets.

Also:
- Add gestureAnimatingRef to prevent double withTiming during gesture opens
- Remove all debug instrumentation added during investigation
- Add Maestro flow and bash script for automated theme-toggle verification
- Add docs/MOBILE_TESTING.md covering Maestro patterns, self-verification
  loops, the Unistyles+Reanimated pitfall, and simulator commands

packages/app/src/contexts/explorer-sidebar-animation-context.tsx

@@ -18,6 +18,8 @@ interface ExplorerSidebarAnimationContextValue {
   animateToOpen: () => void;
   animateToClose: () => void;
   isGesturing: SharedValue<boolean>;
+  gestureAnimatingRef: React.MutableRefObject<boolean>;
+  openGestureRef: React.MutableRefObject<GestureType | undefined>;
   closeGestureRef: React.MutableRefObject<GestureType | undefined>;
 }
 
@@ -39,6 +41,8 @@ export function ExplorerSidebarAnimationProvider({ children }: { children: React
   const translateX = useSharedValue(initialTargets.translateX);
   const backdropOpacity = useSharedValue(initialTargets.backdropOpacity);
   const isGesturing = useSharedValue(false);
+  const gestureAnimatingRef = useRef(false);
+  const openGestureRef = useRef<GestureType | undefined>(undefined);
   const closeGestureRef = useRef<GestureType | undefined>(undefined);
 
   // Track previous isOpen to detect changes
@@ -61,6 +65,11 @@ export function ExplorerSidebarAnimationProvider({ children }: { children: React
       return;
     }
 
+    if (gestureAnimatingRef.current) {
+      gestureAnimatingRef.current = false;
+      return;
+    }
+
     // Don't animate if we're in the middle of a gesture - the gesture handler will handle it
     if (isGesturing.value) {
       return;
@@ -123,6 +132,8 @@ export function ExplorerSidebarAnimationProvider({ children }: { children: React
         animateToOpen,
         animateToClose,
         isGesturing,
+        gestureAnimatingRef,
+        openGestureRef,
         closeGestureRef,
       }}
     >

packages/app/src/contexts/sidebar-animation-context.tsx

@@ -27,6 +27,8 @@ interface SidebarAnimationContextValue {
   animateToOpen: () => void;
   animateToClose: () => void;
   isGesturing: SharedValue<boolean>;
+  gestureAnimatingRef: React.MutableRefObject<boolean>;
+  openGestureRef: React.MutableRefObject<GestureType | undefined>;
   closeGestureRef: React.MutableRefObject<GestureType | undefined>;
 }
 
@@ -46,6 +48,8 @@ export function SidebarAnimationProvider({ children }: { children: ReactNode })
   const translateX = useSharedValue(initialTargets.translateX);
   const backdropOpacity = useSharedValue(initialTargets.backdropOpacity);
   const isGesturing = useSharedValue(false);
+  const gestureAnimatingRef = useRef(false);
+  const openGestureRef = useRef<GestureType | undefined>(undefined);
   const closeGestureRef = useRef<GestureType | undefined>(undefined);
 
   // Track previous isOpen to detect changes
@@ -68,6 +72,14 @@ export function SidebarAnimationProvider({ children }: { children: ReactNode })
       return;
     }
 
+    // Gesture onEnd already started the animation on the UI thread — skip to avoid
+    // a second competing withTiming that can desync translateX and backdropOpacity
+    // after a provider remount (e.g. theme change).
+    if (gestureAnimatingRef.current) {
+      gestureAnimatingRef.current = false;
+      return;
+    }
+
     // Don't animate if we're in the middle of a gesture - the gesture handler will handle it
     if (isGesturing.value) {
       return;
@@ -123,6 +135,8 @@ export function SidebarAnimationProvider({ children }: { children: ReactNode })
       animateToOpen,
       animateToClose,
       isGesturing,
+      gestureAnimatingRef,
+      openGestureRef,
       closeGestureRef,
     }),
     [
@@ -132,6 +146,8 @@ export function SidebarAnimationProvider({ children }: { children: ReactNode })
       animateToOpen,
       animateToClose,
       isGesturing,
+      gestureAnimatingRef,
+      openGestureRef,
       closeGestureRef,
     ],
   );