feat(client/windows): PyroWave decode + surface it in the GUI codec picker

The decoder was gated to Linux because, when it landed, the Windows client
still had its own in-process WinUI/D3D11 presenter and the PyroWave present
path there was an open question. That client has since been retired: Windows
now spawns the SAME Vulkan session presenter as Linux, and the decoder is
plain Vulkan compute on the presenter's device (no fds, no dmabuf, no D3D11
interop), so the question that gated it answered itself. pyrowave-sys already
builds on Windows too -- the Windows HOST encoder ships on it.

So this is a port by un-gating: every cfg(all(target_os = "linux", feature =
"pyrowave")) becomes any(linux, windows) -- decoder module, backend variant,
Decoder::new_pyrowave, the CODEC_PYROWAVE advertisement, the session pump's
opt-in/build/label arms, and the presenter's planar CSC pass. No new code.

Then offer it in the Windows GUI, which is what prompted this. It stays
preference-only (resolve_codec never auto-picks it) and a host or device that
can't do PyroWave just falls back down the ladder to HEVC.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

clients/windows/src/app/settings.rs

@@ -51,6 +51,9 @@ const CODECS: &[(&str, &str)] = &[
     ("hevc", "HEVC (H.265)"),
     ("h264", "H.264 (AVC)"),
     ("av1", "AV1"),
+    // Preference-only by design: `resolve_codec` never auto-picks PyroWave, and asking for
+    // it on a host or device that can't do it simply falls back down the ladder to HEVC.
+    ("pyrowave", "PyroWave (wired LAN)"),
 ];
 /// Virtual-pad presets: `(stored value, display label)` — the pad the HOST creates. Same set the
 /// GTK client offers; "Automatic" resolves from the physical controller at connect.
@@ -278,7 +281,7 @@ pub(crate) fn settings_page(
         s.codec = CODECS[i].0.to_string();
     })
     .tooltip(
-        "A soft preference \u{2014} the host falls back to the best codec both sides support.",
+        "A soft preference \u{2014} the host falls back to the best codec both sides support.          PyroWave is the low-latency wavelet codec for a WIRED link: it trades bitrate          (hundreds of Mb/s) for near-zero decode time, so it needs gigabit Ethernet.",
     );
     // Free-form Mb/s (0 = host default) instead of presets, so a speed-test recommendation
     // round-trips exactly.