fix: mobile terminal scroll in both normal mode and tmux

- Dual-mode touch scroll:
  - Normal mode: scroll .xterm-viewport directly when scrollHeight > clientHeight
  - Alternate screen (tmux/vim): send SGR 1006 mouse-wheel protocol data
    using cursor position so tmux knows which pane to scroll
- Add touch-action: none to .terminal-container to prevent browser gestures
- Lock both html and body overflow when terminal page is open on mobile
- Remove synthetic WheelEvent approach (xterm.js SmoothScrollableElement
  doesn't reliably handle synthetic events)

apps/web/src/pages/terminal.tsx

@@ -204,12 +204,14 @@ export const TerminalPage: React.FC = () => {
 		};
 	}, []);
 
-	// Lock body scroll on mobile terminal so swipes scroll the terminal buffer,
+	// Lock page scroll on mobile terminal so swipes scroll the terminal buffer,
 	// not the page.
 	useEffect(() => {
 		if (!isMobile) return;
+		document.documentElement.classList.add("terminal-page-open");
 		document.body.classList.add("terminal-page-open");
 		return () => {
+			document.documentElement.classList.remove("terminal-page-open");
 			document.body.classList.remove("terminal-page-open");
 		};
 	}, [isMobile]);