Native support for MX Master 3S Gesture Button on macOS, including space-switching and drag debouncing.

## Background

I downloaded OpenLogi hoping to remap the **thumb-rest gesture button** on my **Logitech MX Master 3S** on macOS. Unfortunately, the gesture button was completely undetected, clicking it produced no response in the app, no button events, nothing. It appeared to be completely dead at the OS level.

Rather than giving up, I decided to reverse-engineer what was actually happening using **Gemini 3.5 Flash** (Google's AI assistant). Over a long debugging session, we:

1. Wrote a raw **Quartz Event Tap event sniffer** in Rust to log every mouse and keyboard event at the OS level
2. Tested the button with and without Logitech Options+ installed
3. Discovered that without **any** Logitech drivers, the gesture button natively registers as **mouse Button 5**
4. Worked through several layers of macOS sandbox restrictions to get space-switching working reliably

Sharing all findings here in case they are useful to integrate into OpenLogi.

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## 1. 🖱️ Native Gesture Button 5 Hook (No HID++ Diversion Required)

**Discovery:** When Logitech proprietary drivers are fully uninstalled on macOS, the physical thumb-rest gesture button on MX Master 3S natively reports to the OS as standard mouse **Button 5** via `CGEventType::OtherMouseDown/Up`, rather than being completely silent or requiring raw HID++ 2.0 vendor diversion packets.

This means a lightweight Quartz Event Tap can intercept it directly — no `REPROG_CONTROLS_V4` feature negotiation or USB HID++ vendor page access n...