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/app.js

@@ -1051,33 +1051,6 @@ document.addEventListener('DOMContentLoaded', () => {
   document.addEventListener('click', trackInteraction);
   document.addEventListener('touchstart', trackInteraction);
 
-  // ---------------------------------------------------------------------------
-  // Sidebar touch scroll — manual scrollTop manipulation bypasses the CSS
-  // touch-scroll path that fails when position:fixed + overflow:hidden is on
-  // the parent (.session-sidebar) in mobile overlay mode.
-  // ---------------------------------------------------------------------------
-  ;(function initSidebarTouchScroll() {
-    var list = document.querySelector('.sidebar-list');
-    if (!list || typeof list.addEventListener !== 'function') return;
-
-    var _lastY = 0;
-
-    list.addEventListener('touchstart', function (e) {
-      _lastY = e.touches[0].clientY;
-    }, { passive: true });
-
-    list.addEventListener('touchmove', function (e) {
-      e.preventDefault();                        // block page scroll
-      var y = e.touches[0].clientY;
-      list.scrollTop += _lastY - y;              // direct scrollTop — always works
-      _lastY = y;
-    }, { passive: false });                      // passive:false required for preventDefault
-
-    list.addEventListener('touchend', function () {
-      _lastY = 0;
-    }, { passive: true });
-  })();
-
   restoreState()
     .then(() => {
       startPolling();

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 });
-})();

muxplex/frontend/tests/test_app.mjs

@@ -40,7 +40,6 @@ Object.defineProperty(globalThis, 'navigator', {
   configurable: true,
 });
 
-import fs from 'node:fs';
 import { createRequire } from 'node:module';
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
@@ -2026,13 +2025,4 @@ test('bindSidebarClickAway registers click listener on terminal-container', () =
   globalThis.document.getElementById = origGetById;
 });
 
-// --- Sidebar touch scroll ---
 
-test('app.js has sidebar touch scroll handler that uses scrollTop', () => {
-  const source = fs.readFileSync(
-    new URL('../app.js', import.meta.url), 'utf8'
-  );
-  assert.ok(source.includes('sidebar-list'), 'must target .sidebar-list');
-  assert.ok(source.includes('scrollTop'), 'must use scrollTop (not scrollLines or WheelEvent)');
-  assert.ok(source.includes('passive: false'), 'touchmove must be non-passive to allow preventDefault');
-});

muxplex/frontend/tests/test_terminal.mjs

@@ -5,7 +5,6 @@ import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import { fileURLToPath } from 'node:url';
 import { dirname, join } from 'node:path';
-import fs from 'node:fs';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
@@ -719,40 +718,4 @@ test('terminal is auto-focused when WebSocket opens', () => {
     '_term.focus() should be called exactly once when the WebSocket open event fires');
 });
 
-// --- Touch scroll source-inspection tests ---
 
-const terminalSrc = fs.readFileSync(
-  new URL('../terminal.js', import.meta.url), 'utf8'
-);
-
-test('terminal.js touchmove dispatches WheelEvent to xterm viewport', () => {
-  assert.ok(terminalSrc.includes('touchmove'), 'touchmove listener must be present');
-  assert.ok(terminalSrc.includes('e.preventDefault'), 'must call preventDefault to prevent page scroll');
-  assert.ok(terminalSrc.includes('WheelEvent'), 'must dispatch WheelEvent (not call scrollLines)');
-  assert.ok(terminalSrc.includes('.xterm-viewport'), 'must target xterm viewport element');
-  assert.ok(!terminalSrc.includes('scrollLines'), 'must NOT call scrollLines — that only moves local scrollback, not the PTY');
-  assert.ok(terminalSrc.includes('passive: false'), 'touchmove must be non-passive to allow preventDefault');
-});
-
-test('terminal.js touchstart and touchend are passive', () => {
-  // touchstart and touchend should be passive: true for performance
-  // (they don't need preventDefault)
-  const touchstartPassive = terminalSrc.match(/touchstart[\s\S]*?passive:\s*(true|false)/);
-  const touchendPassive   = terminalSrc.match(/touchend[\s\S]*?passive:\s*(true|false)/);
-  assert.ok(touchstartPassive, 'touchstart listener must declare passive');
-  assert.ok(touchendPassive,   'touchend listener must declare passive');
-});
-
-test('terminal.js touchmove uses accumulation for consistent scroll steps', () => {
-  const source = fs.readFileSync(
-    new URL('../terminal.js', import.meta.url), 'utf8'
-  );
-  assert.ok(source.includes('touchmove'), 'touchmove listener must be present');
-  assert.ok(source.includes('e.preventDefault'), 'must call preventDefault');
-  assert.ok(source.includes('WheelEvent'), 'must dispatch WheelEvent');
-  assert.ok(source.includes('.xterm-viewport'), 'must target xterm viewport');
-  assert.ok(source.includes('_accumulated'), 'must accumulate delta between events');
-  assert.ok(source.includes('SCROLL_PX'), 'must use a threshold constant');
-  assert.ok(!source.includes('deltaY * 3'), 'must NOT use variable deltaY scaling (causes jumpy scroll)');
-  assert.ok(source.includes('passive: false'), 'touchmove must be non-passive');
-});