feat: implement mobile app usability improvements

Mobile Navigation:
- Add MobileNav component with bottom tab bar
- Show mobile nav on small screens, hide desktop sidebar
- Add session count badge to Sessions tab
- Add safe area padding for notched devices

Session Management:
- Redesign SessionCard for mobile with action menu
- Add MobileActionSheet for session actions
- Keep primary action prominent

Forms & Dialogs:
- Stack form fields vertically on mobile
- Ensure 44px minimum touch targets
- Update dialogs for 320px viewport

Responsive Layout:
- Add MobilePageHeader with back button
- Reduce page padding on mobile
- Stack multi-column grids vertically

Touch & Interaction:
- Add active states to interactive elements
- Ensure 8px spacing between touch targets

Complex Pages:
- Update Repo Workspace for mobile
- Update Tool Workshop and Config Profiles

Build: TypeScript check passes, production build succeeds

apps/web/src/components/special-keys-strip.tsx

@@ -1,5 +1,5 @@
 import React from "react";
-import { getSequenceWithModifier, type SpecialKey, type ModifierKey, KEY_SEQUENCES } from "../hooks/use-special-keys";
+import { getSequenceWithModifier, type SpecialKey, type ModifierKey } from "../hooks/use-special-keys";
 
 interface SpecialKeysStripProps {
   onSend: (data: string) => void;