feat: implement mobile terminal UX

- Add mobile viewport detection hook
- Add virtual keyboard detection with fallback
- Add auto-hide hook for header/keys strip
- Add special keys mapping hook
- Create MobileTerminalHeader, SpecialKeysStrip, SpecialKeysPanel components
- Create MobileTerminalWrapper component
- Update TerminalComponent with mobile support, font scaling, copy/paste, reconnection
- Update AppShell to hide chrome on mobile terminal pages
- Update TerminalPage to use MobileTerminalWrapper
- Add comprehensive mobile terminal styles
- TypeScript check passes
- Build succeeds

apps/web/src/hooks/use-auto-hide.ts

@@ -0,0 +1,68 @@
+import { useState, useEffect, useCallback, useRef } from "react";
+
+interface AutoHideOptions {
+  timeout?: number;
+  enabled?: boolean;
+}
+
+export function useAutoHide(options: AutoHideOptions = {}) {
+  const { timeout = 3000, enabled = true } = options;
+  const [isVisible, setIsVisible] = useState(true);
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const lastInteractionRef = useRef(Date.now());
+
+  const show = useCallback(() => {
+    if (!enabled) return;
+    setIsVisible(true);
+    lastInteractionRef.current = Date.now();
+
+    if (timerRef.current) {
+      clearTimeout(timerRef.current);
+    }
+
+    timerRef.current = setTimeout(() => {
+      setIsVisible(false);
+    }, timeout);
+  }, [enabled, timeout]);
+
+  const hide = useCallback(() => {
+    if (!enabled) return;
+    setIsVisible(false);
+    if (timerRef.current) {
+      clearTimeout(timerRef.current);
+      timerRef.current = null;
+    }
+  }, [enabled]);
+
+  const toggle = useCallback(() => {
+    if (!enabled) return;
+    if (isVisible) {
+      hide();
+    } else {
+      show();
+    }
+  }, [enabled, isVisible, show, hide]);
+
+  useEffect(() => {
+    if (!enabled) {
+      setIsVisible(true);
+      return;
+    }
+
+    // Start the timer initially
+    show();
+
+    return () => {
+      if (timerRef.current) {
+        clearTimeout(timerRef.current);
+      }
+    };
+  }, [enabled, show]);
+
+  return {
+    isVisible,
+    show,
+    hide,
+    toggle,
+  };
+}