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/terminal.tsx

@@ -241,7 +241,6 @@ export const TerminalComponent: React.FC<TerminalProps> = ({
     term.loadAddon(new WebLinksAddon());
 
     const container = terminalRef.current;
-    let ws: WebSocket;
 
     // Define fitTerminal before connectWebSocket so it's available in onmessage
     const fitTerminal = () => {
@@ -272,7 +271,7 @@ export const TerminalComponent: React.FC<TerminalProps> = ({
 
     // Open xterm first (must happen before fit)
     term.open(container);
-    ws = connectWebSocket();
+    const ws = connectWebSocket();
 
     // Initial fit after layout settles (terminal must be opened first)
     let fitAttempts = 0;