Add Surface Pro 11 ambient light sensor support

[turbineBMW]

Summary

• The Surface Pro 11's light sensor sits on the ADSP's Qualcomm sensor core, which reports nothing until the host serves its configuration.
• Builds hexagonrpcd (with registry write support) and libssc (reading Microsoft's color sensor) from pinned upstream source into a private directory, and points iio-sensor-proxy at that libssc with a drop-in. Arch's iio-sensor-proxy is otherwise untouched. The libssc pin includes the fix for iio-sensor-proxy spinning when the sensor server never appears.
• The sensor configuration is Microsoft's and Qualcomm's and is not shipped. surface-pro-11-sensors-extract copies it from the machine's own Windows driver store, the same model as qcom-firmware-extract (Add safe Windows firmware extraction for Snapdragon laptops #221). It runs only on the Surface Pro 11 OLED (device-tree gated) and reuses an already mounted Windows partition.
• The service starts when the ADSP device appears, so a missing DSP never delays boot. A sleep hook stops iio-sensor-proxy across suspend so the light stream does not wake the SoC.
• groups=('omarchy-platform-qualcomm'), edge.

Consumers: the ALS keyboard-backlight work in omarchy#13148 and auto-brightness.

Dependencies

None to build. Needs the ADSP running, so the Surface DSP firmware from #221 (with the Windows-name fix offered there).

Test plan

• test.sh and hexagonrpc's tests pass
• The extracted configuration matches the previously qualified one byte for byte
• The service starts from the ADSP device; monitor-sensor --light reports live illuminance (about 30 lux indoors, over 100 in daylight) on kernel 7.3-rc6
• Readings continue after suspend and resume