feat(WASAPI): allow setting raw stream mode

[infiniwave]

Closes #1173. Has not yet been tested on other platforms than Windows.

[roderickvd]

Thank you for this PR. Selectable raw mode is definitely something we should support. The question is of API design; a few different ideas have been proposed (builder in #1010, trait extensions in #1074, yours). I first want to get v0.18 out of the door and then pick up that discussion and decide how.

[1rhino2]

windows review notes on this tip.

what works

• the WASAPI call site looks right: SetClientProperties with AUDCLNT_STREAMOPTIONS_RAW before Initialize, gated on IAudioClient2.
• cargo check --all-targets is green on the PR branch here (x86_64-pc-windows-gnu).
• solves the real pain from #1173 (shared-mode capture going through the system AEC/NS/AGC path).

design tension with #1220

• the v0.19 tracker lists RAW mode under "work out extension traits" (#1173), same bucket as ASIO control panel / PipeWire NO_CONVERT.
• this PR puts AudioProcessing on the shared StreamConfig instead. that is a breaking public-API addition and may not match the extension-trait direction @roderickvd is pushing in #1074.
• before merge i'd want an explicit call from maintainers: StreamConfig field vs WasapiDeviceExt / stream-option trait. if extension traits win, this should be reshaped rather than landing as-is.

other nits

• ~96 commits behind master; needs rebase. master still has bare StreamConfig { channels, sample_rate, buffer_size } literals (e.g. coreaudio ios) that will need the new field or ...
• no CHANGELOG / UPGRADING note for the breaking StreamConfig shape.
• SetClientProperties(...).ok() makes PreferRaw a silent no-op on failure. at least a debug log (or surface UnsupportedOperation when PreferRaw was requested and the call failed / IAudioClient2 missing) would help apps that think they got raw.
• AudioClientProperties leaves eCategory at Default. worth confirming against current windows-rs / WASAPI docs whether category should be set explicitly when Options=RAW.

couldn't finish a live PreferRaw smoke here: this host is windows-gnu without a working dlltool/link path, so binaries don't link even though check passes. happy to re-run once i have an msvc or mingw linker, or if someone else posts a short capture A/B.

[roderickvd]

I haven’t decided yet on the extensions traits design. I’m working on a discussion piece on my other machine, that I don’t have access to right now.

When something like a qualified majority (no hard rule) of hosts support raw and/or exclusive with the same semantics, then it may warrant something on StreamConfig regardless - could live alongside extension traits too. (Is raw / exclusive / hog / passthrough mode whatever something in stream though or on the device?)

Long story short, we need to work it out properly before we can commit to a design.