Goal

Make one-finger vertical swipes on the workspace terminal scroll tmux (and other mouse-aware apps) the same way mouse-wheel scrolling does today.

Scope

• In scope: browser-side change in the workspace/job terminal host (server-core/.../web/component/terminal/terminal.js), plus updating the scroll tip on WorkspaceTerminalPage.
• Out of scope: tmux/container config, server PTY / WebSocket protocol changes. Existing SHELL_INPUT / mouse-protocol path already works for wheel; touch just never reaches it.

Why this location

terminal.js creates a stock xterm.js instance and forwards onData to the WebSocket. Wheel scrolling already works because xterm.js turns wheel events into mouse-protocol sequences when the app enables mouse reporting. The bundled xterm does listen for touch, but that path is for its own gesture handling, not for synthesizing wheel / mouse-wheel buttons for apps like tmux. OneDev should bridge that gap in our wrapper rather than forking xterm.

Approach

1. After xterm.open(...), attach touchstart / touchmove / touchend / touchcancel listeners on the terminal DOM element (non-passive where we need preventDefault).
2. On single-finger vertical pans:
   • accumulate deltaY from touch movement
   • emit synthetic WheelEvents (deltaMode: DOM_DELTA_PIXEL) on the xterm screen element so the existing mouse-tracking / alt-buffer wheel handlers run unchanged
3. Gesture rules:
   • ignore multi-touch (pinch / two-finger)
   • ignore mostly-horizontal pans (leave page swipe / selection alone)
   • use a small movement threshold so taps still focus / place the cursor
   • preventDefault only after a vertical scroll gesture is recognized, so we do not break tap-to-focus
4. Keep server code (TerminalPanel, WebSocket messages) unchanged; synthesized wheel input continues to flow as SHELL_INPUT via xterm's normal mouse encoding.
5. Update the tippy help text on the terminal page to mention touch swipe when mouse mode is active, and keep the existing Ctrl-b [ copy-mode hint as a fallback.

Edge cases / acceptance

Test plan

• Touch device or browser device emulation against a workspace terminal.
• Verify tmux mouse scroll, plain shell, and that mouse wheel / keyboard still work.
• Smoke-test job terminal pages that reuse TerminalPanel / terminal.js.

Follow-up (optional, not required for first cut)

• Tune swipe sensitivity / inertia to feel closer to native terminals.
• Consider contributing or aligning with upstream xterm.js touch→wheel behavior so a future xterm bump can replace the local bridge.

If this plan looks right, we can open an enhancement issue (or retarget this one) and implement it.