Menu bar items trigger click action on hover (mouse only) when using custom title bar

Type: Bug

### Does this issue occur when all extensions are disabled?
Not yet tested — please verify with `code --disable-extensions` before filing, and update this line with the result.

### Steps to Reproduce

1. Ensure `window.titleBarStyle` is set to `"custom"` (the default) in `settings.json`.
2. Open VS Code with the custom title bar / integrated menu bar visible.
3. Using only the mouse (no clicking), hover over any top-level menu item (e.g. **File**, **Edit**, **View**).
4. Observe that the menu item's click action fires just from hovering, without an actual mouse click.

### Expected behavior
Hovering over a top-level menu item should only highlight/preview it. The menu should only open, or an action should only fire, on an actual mouse click (or via keyboard mnemonics/Alt navigation, where hover-switching between already-open menus is expected).

### Actual behavior
Menu items respond to hover alone as if clicked, without any mouse button being pressed.

### Workaround found
Switching `window.titleBarStyle` to `"native"` resolves the issue completely — the native Windows-rendered menu does not exhibit this hover-click behavior. This points to the bug being specific to VS Code's custom Electron-rendered menu bar rather than Windows or the mouse hardware.

### Environment
- **VS Code Version:** 1.132.0 (system setup)
- **Commit:** df53daabb18cd157bdb08c7f01c34df936cf1... *(paste the full commit hash from Help → About if needed)*
- **Date:** 2026-08-04T15:30:20Z
- **Electron:** 42.7.1
- **Chromium:** 148.0.7778.280
- **Node.js:** 24.18.0
- **V8:** 14.8.178.38-electron.0
- **OS:** Windows_NT x64 10.0.26200
- **window.titleBarStyle:** custom (bug present) / native (bug absent)

### Additional context
This only occurs in VS Code — other Windows applications' menu bars behave normally (hover highlights, click activates). This suggests the issue lies in VS Code's custom title bar/menu rendering rather than an OS-level accessibility setting (e.g. dwell click) or mouse driver.

VS Code version: Code 1.132.0 (df53daabb18cd157bdb08c7f01c34df936cf12f4, 2026-08-04T15:30:20Z)
OS version: Windows_NT x64 10.0.26200
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|AMD Ryzen 7 5800H with Radeon Graphics (16 x 3194)|
|GPU Status|2d_canvas: enabled
GPU0: VENDOR= 0x1002, DEVICE=0x1638 [AMD Radeon(TM) Graphics], DRIVER_VENDOR=AMD, DRIVER_VERSION=31.0.12044.37003 *ACTIVE*
GPU1: VENDOR= 0x10de, DEVICE=0x25a2 [NVIDIA GeForce RTX 3050 Laptop GPU], DRIVER_VERSION=32.0.15.6607
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.26100.8972
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: enabled
multiple_raster_threads: enabled_on
opengl: enabled_on
rasterization: enabled
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: enabled
video_encode: enabled
webgl: enabled
webgpu: enabled
webnn: disabled_off|
|Load (avg)|undefined|
|Memory (System)|15.41GB (7.25GB free)|
|Process Argv|--crash-reporter-id 6f112c88-36c3-498d-9659-5aa293597eb4|
|Screen Reader|yes|
|VM|0%|
Extensions: none
A/B Experiments

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session-mark-done:31558131

```