feat(desktop): support Ctrl/Cmd + mouse wheel zoom

[liuhao1024]

Summary

Adds the standard desktop/browser zoom gesture: Ctrl (Windows/Linux) or Cmd (macOS) + mouse wheel up/down to zoom in/out.

This is the most common zoom gesture in desktop applications and browsers. Hermes Desktop already supports keyboard shortcuts (Ctrl/Cmd + +/-/0) and View menu zoom actions, but this gesture was missing.

Implementation

• Main process (main.cjs): installWheelZoom() injects a lightweight wheel event listener into the renderer via executeJavaScript on dom-ready and did-finish-load
• Renderer listener: detects Ctrl/Cmd + wheel, calls e.preventDefault() to block page scroll, sends a zoom delta over IPC (hermes:zoom:adjust)
• IPC handler: clamps zoom level to [-9, 9] with 0.1 step — matching the existing keyboard zoom step from installZoomShortcuts
• Preload (preload.cjs): exposes zoomAdjust(delta) via ipcRenderer.send
• Types (global.d.ts): adds zoomAdjust?: (delta: number) => void to the hermesDesktop interface

Behavior

Gesture	Action
Ctrl/Cmd + wheel up	Zoom in (+0.1)
Ctrl/Cmd + wheel down	Zoom out (-0.1)
Ctrl/Cmd + 0	Reset to 100% (existing)

Testing

1. Open Hermes Desktop
2. Hold Ctrl (or Cmd on macOS) and scroll the mouse wheel up → text should get larger
3. Hold Ctrl/Cmd and scroll down → text should get smaller
4. Press Ctrl/Cmd+0 → zoom resets to 100%
5. Zoom persists across SPA route changes (re-injected on did-finish-load)

Closes #40295

[teknium1]

Thanks for the useful desktop ergonomics contribution. The gesture remains worth salvaging, but this implementation needs a current-main port.

Problems

• apps/desktop/electron/main.cjs and preload.cjs were renamed to TypeScript in 39d09453f; neither CJS path is tracked on current main.
• The added wc.setZoomLevel(next) bypasses current main's setAndPersistZoomLevel() at apps/desktop/electron/main.ts:4766-4780, which persists zoom and emits hermes:zoom:changed for the settings UI.
• Current IPC targets the sender's window at apps/desktop/electron/main.ts:7442-7455; preserve that per-window routing because zoom is wired for both primary and secondary chat windows (apps/desktop/electron/main.ts:6972-6981, 7063, 7307).

Suggested changes

• Port the listener and bridge to main.ts / preload.ts, and route adjustments through the existing sender-derived zoom path and setAndPersistZoomLevel().
• Add coverage for modifier/direction plus persistence and settings synchronization.

Automated hermes-sweeper review.

[teknium1]

Merged via PR #67029 (#67029) — the Ctrl/Cmd + wheel zoom gesture is on main with your authorship preserved via rebase-merge. Thanks for the contribution and the clear writeup!

One implementation note: your branch predated the desktop TypeScript migration, so the change was reapplied under your authorship rather than cherry-picked — and in the process we found Electron now surfaces the modifier+wheel gesture natively as the main-process zoom-changed event. The merged version listens to that instead of injecting a renderer script + IPC channel, and routes through the shared zoom funnel so the gesture picks up persistence (zoom survives restarts) and settings-UI sync for free.

Closing this PR in favor of the merged salvage. Thanks again!