revert: remove JS touch scroll handlers — back to mouse-only baseline

Removing terminal WheelEvent dispatch and sidebar scrollTop handlers.
CSS fixes retained (touch-action:pan-y, overscroll-behavior:contain,
flex-shrink:0). Testing mouse-only baseline across all devices before
deciding on the right mobile scroll approach.

muxplex/frontend/terminal.js

@@ -247,53 +247,4 @@ function closeTerminal() {
 window._openTerminal = openTerminal;
 window._closeTerminal = closeTerminal;
 
-// ---------------------------------------------------------------------------
-// Touch scroll — accumulates delta and dispatches fixed-size WheelEvents.
-// Fixed deltaY=120 per SCROLL_PX pixels ensures consistent scroll steps
-// regardless of how Android Chrome batches touchmove events. Each WheelEvent
-// travels through xterm.js mouse reporting to tmux (the "inside" path).
-// Mouse wheel (wheel event) and iOS/desktop are unaffected.
-// ---------------------------------------------------------------------------
-;(function initTerminalTouchScroll() {
-  var container = document.getElementById('terminal-container');
-  if (!container || typeof container.addEventListener !== 'function') return;
 
-  var _touchLastY = 0;
-  var _accumulated = 0;         // running pixel debt between scroll events
-  var SCROLL_PX = 20;           // pixels of touch movement = one scroll click
-
-  container.addEventListener('touchstart', function (e) {
-    _touchLastY = e.touches[0].clientY;
-    _accumulated = 0;           // reset on new touch
-  }, { passive: true });
-
-  container.addEventListener('touchmove', function (e) {
-    if (!_term) return;
-    e.preventDefault();
-
-    var y = e.touches[0].clientY;
-    _accumulated += _touchLastY - y;   // accumulate — positive = swipe up
-    _touchLastY = y;
-
-    var viewport = container.querySelector('.xterm-viewport');
-    if (!viewport) return;
-
-    // Fire one standard-sized click (deltaY=120) per SCROLL_PX pixels.
-    // Fixed deltaY makes every step identical regardless of Android event batching.
-    while (Math.abs(_accumulated) >= SCROLL_PX) {
-      var dir = _accumulated > 0 ? 1 : -1;
-      viewport.dispatchEvent(new WheelEvent('wheel', {
-        deltaY: dir * 120,         // 120 = one standard wheel click, consistent
-        deltaMode: WheelEvent.DOM_DELTA_PIXEL,
-        bubbles: true,
-        cancelable: true,
-      }));
-      _accumulated -= dir * SCROLL_PX;
-    }
-  }, { passive: false }); // passive: false required to allow e.preventDefault()
-
-  container.addEventListener('touchend', function () {
-    _touchLastY = 0;
-    _accumulated = 0;           // discard sub-threshold remainder on lift
-  }, { passive: true });
-})();