Add safe Windows firmware extraction for Snapdragon laptops

[birkskyum]

Summary

• adds Jimmy Van Veen's original qcom-firmware-extract package without fork-specific integration changes
• reads firmware filenames requested by the running Qualcomm device tree
• stages vendor-signed files from a Windows DriverStore before installation can overwrite Windows
• installs staged files under /usr/lib/firmware/updates on the target
• selects among multiple Windows firmware variants by matching a sibling blob already installed for the same remote processor
• refuses an ambiguous incompatible choice instead of silently choosing the newest variant

Provenance

The package and original extractor commit are authored by Jimmy Van Veen and extracted cleanly from JimmayVV/omarchy-pkgs@snapdragon. The matching follow-up is authored by Birk Skyum from the Lenovo Yoga Slim 7x installation findings.

Why the matching check matters

The Yoga Windows DriverStore contained multiple cdsp_dtbs.elf variants. Picking the newest file selected the wrong board firmware. The working variant was identifiable because its sibling qccdsp8380.mbn hash matched the installed firmware for that device-tree node. The extractor now uses that relationship and supports zstd, xz and gzip-compressed installed companions.

Validation

• the focused test recreates the Lenovo multi-variant case and selects the correct older DTB by companion hash
• the extracted firmware was used to start both ADSP and CDSP on a Lenovo Yoga Slim 7x
• shell syntax and git whitespace checks pass

The wider Snapdragon ISO and runtime dependencies are tracked in omacom/omarchy-iso#129 and omacom/omarchy#8672.

[JimmayVV]

Confirming provenance. qcom-firmware-extract is mine. The companion-hash matching is a real improvement. The "newest wins" rule was only ever tested against one driver store. Thanks for catching it.