fix: enable native touch scrolling on xterm.js viewport for mobile

- Remove all custom touch event interception code from terminal.tsx
- After term.open(), find the internal .xterm-viewport element and set
  touchAction=pan-y and overscrollBehavior=contain via inline styles
- Add CSS targeting .xterm-viewport on mobile with touch-action: pan-y,
  -webkit-overflow-scrolling: touch, and overflow-y: auto
- Let the browser handle vertical touch panning natively instead of
  trying to intercept and manually forward events

apps/web/src/styles.css

@@ -3709,6 +3709,14 @@ a.nav-item,
 
 /* xterm.js manages its own scrolling and viewport dimensions */
 
+/* Mobile: enable native touch scrolling on xterm viewport */
+.terminal-wrapper.mobile .xterm .xterm-viewport {
+	touch-action: pan-y !important;
+	-webkit-overflow-scrolling: touch !important;
+	overflow-y: auto !important;
+	scrollbar-width: none;
+}
+
 /* Special Keys Strip */
 .special-keys-strip {
 	flex-shrink: 0;