Prepare zero-warning Windows and Linux app release

[worflor]

What changed

• Make Clippy a zero-warning workspace gate and fix the underlying Rust warnings across Windows and Linux.
• Build and ship the Slint app with the CLI on Linux, with a GTK tray and honest messaging for Linux input features that still need backends.
• Add local packaging for the Windows installer, Windows portable zip, and Linux app/CLI tarball; correct validation and release scripts for those assets.
• Fix aligned HID control buffers, release a Win32 thread-description allocation, and handle hotplug notifier startup failure.
• Document the libxkbcommon-x11 dependency discovered by launching the Linux GUI, and make Git ignore Windows build-cache junctions when viewed from WSL.

Verification

• Windows ./validate.ps1 -Mode full -Locked: all gates green, including tests, Clippy, feature matrix, release build, and CI-safe ignored tests.
• Linux pwsh ./validate.ps1 -Locked: all gates green with neuron-app included. Workspace Clippy also passed with -D warnings.
• Windows lint mode passed PowerShell parsing; rustfmt remains advisory under the repository's hand-formatting rule.
• Ubuntu 22.04 built the app and CLI in release mode. The packaged binaries have a measured GLIBC_2.35 floor; the extracted CLI reports 0.1.0 and the extracted GUI opens under WSLg with its GTK tray.
• Windows portable zip extracts and its CLI runs. The Inno Setup installer completed a silent install, its installed CLI ran, and its uninstaller completed successfully.
• BlackWidow Chroma V2 (0221) and Naga V2 Pro (00a8) hardware-mode read-back succeeded before stopping the resident app for release builds. The resident tray app was restarted afterward. No Linux Razer hardware was available.

Before this can merge

• I have read and agree to the Woflo Labs Contributor Agreement 1.0 (July 19, 2026) as it is committed on this pull request's base branch when I record this acceptance. I accept it for this contribution and have authority to submit it.