fix: xterm.js mobile touch scrolling via viewport CSS and stopPropagation

- Add full mobile viewport CSS: overflow-y scroll, -webkit-overflow-scrolling
  touch, overscroll-behavior-y contain, translate3d hardware accel,
  scroll-behavior smooth, touch-action pan-y
- After term.open(), find .xterm-viewport and add passive touch listeners
  that call stopPropagation() (not preventDefault) — this lets the browser
  handle native touch scrolling while preventing xterm.js internal handlers
  from interfering
- Based on xterm.js known issue #5489 and SCROLLING_FIX.md approach

apps/web/src/components/terminal.tsx

@@ -311,6 +311,37 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 			// Open xterm first (must happen before fit)
 			term.open(container);
 			term.focus();
+
+			// Mobile: allow native touch scroll on xterm viewport.
+			// xterm.js 5.x+ uses SmoothScrollableElement which can block native
+			// touch scrolling. We add passive touch listeners that call
+			// stopPropagation (not preventDefault) so the browser handles the
+			// gesture natively while xterm.js internal handlers don't fire.
+			let touchCleanup: (() => void) | undefined;
+			if (isMobile) {
+				const viewport = container.querySelector(
+					".xterm-viewport",
+				) as HTMLElement | null;
+				if (viewport) {
+					const onTouchStart = (e: TouchEvent) => {
+						e.stopPropagation();
+					};
+					const onTouchMove = (e: TouchEvent) => {
+						e.stopPropagation();
+					};
+					viewport.addEventListener("touchstart", onTouchStart, {
+						passive: true,
+					});
+					viewport.addEventListener("touchmove", onTouchMove, {
+						passive: true,
+					});
+					touchCleanup = () => {
+						viewport.removeEventListener("touchstart", onTouchStart);
+						viewport.removeEventListener("touchmove", onTouchMove);
+					};
+				}
+			}
+
 			const ws = connectWebSocket();
 
 			// Initial fit after layout settles (terminal must be opened first)
@@ -429,8 +460,6 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 			};
 			document.addEventListener("visibilitychange", handleVisibilityChange);
 
-
-
 			return () => {
 				isUnmountingRef.current = true;
 				clearTimeout(resizeTimeout);
@@ -442,6 +471,7 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 					"visibilitychange",
 					handleVisibilityChange,
 				);
+				if (touchCleanup) touchCleanup();
 				if (ws) {
 					ws.close(1000, "Component unmounting");
 				}