fix(mobile): swallow blank-space long presses

src/web/public/terminal-ui.js

@@ -1934,24 +1934,22 @@ Object.assign(CodemanApp.prototype, {
     this.terminal?.select?.(index % cols, Math.floor(index / cols), length);
   },
 
-  /** Long-press fired: select the word under the finger and arm drag-to-extend. */
+  /** Long-press fired: swallow the platform gesture, then select a word if one exists. */
   _beginTouchSelection(clientX, clientY) {
+    // Reaching the 350ms threshold makes this a long press even when the finger
+    // landed on blank space. Arm every guard before looking for a word so Chrome
+    // cannot focus xterm's hidden textarea, and leave _touchSelecting set so the
+    // touchend branch preventDefaults the compatibility mouse sequence.
+    this._blurMobileTerminalInput();
+    this._suppressTrustedTapMouseEvents();
+    this._armTouchSelectionFocusGuard();
+    this._touchSelecting = true;
     const cell = this._touchSelectionCellAt(clientX, clientY);
     if (!cell) return false;
     const word = this._touchSelectionWordAt(cell);
     if (!word) return false;
-    // The keyboard must not sit on top of the thing being selected, and the
-    // composer would eat the selection on its next keystroke anyway.
-    this._blurMobileTerminalInput();
     this._touchSelectionAnchor = word;
-    this._touchSelecting = true;
     this._touchSelectionActive = true;
-    // From here until the gesture ends, no trusted mouse event may reach xterm —
-    // see _endTouchSelectionGesture for why — and the terminal input may not take
-    // focus. Both are re-armed as the gesture continues, since their windows are
-    // short and a press can be held for much longer.
-    this._suppressTrustedTapMouseEvents();
-    this._armTouchSelectionFocusGuard();
     this._applyTouchSelection(word.index, word.length);
     // Android answers; iOS ignores it silently. Both are fine.
     try {

test/terminal-touch-tap.test.ts

@@ -987,11 +987,24 @@ describe('terminal touch selection', () => {
     expect(select).toHaveBeenCalledWith(PATH_AT, 0, '/tmp/out/chart.png'.length);
   });
 
-  it('selects nothing when the press lands on blank space', () => {
+  it('swallows a blank-space long press without creating a selection', () => {
     const { app, select } = selectionHarness();
+    app._blurMobileTerminalInput = vi.fn();
+    app._suppressTrustedTapMouseEvents = vi.fn();
+    app._armTouchSelectionFocusGuard = vi.fn();
+    app._showTouchSelectionBar = vi.fn();
 
     expect(press(app, LINE.length + 10)).toBe(false);
+    expect(app._blurMobileTerminalInput).toHaveBeenCalledOnce();
+    expect(app._suppressTrustedTapMouseEvents).toHaveBeenCalledOnce();
+    expect(app._armTouchSelectionFocusGuard).toHaveBeenCalledOnce();
+    // touchend keys off this state to preventDefault the compatibility mouse
+    // sequence even though blank space produced no selection to keep alive.
+    expect(app._touchSelecting).toBe(true);
+    expect(app._touchSelectionActive).toBeFalsy();
+    expect(app._touchSelectionAnchor).toBeUndefined();
     expect(select).not.toHaveBeenCalled();
+    expect(app._showTouchSelectionBar).not.toHaveBeenCalled();
   });
 
   it('grows the selection as the finger drags past the anchor word', () => {