feat(host,clients): PyroWave ships in default builds; NVIDIA hosts advertise it

Flip the `pyrowave` cargo feature into the default set across punktfunk-host,
pf-client-core, pf-presenter and the session client — every packaged build
(flatpak, arch/rpm/copr, windows x64 client) now carries the codec. Selection
stays strictly per-session opt-in: a client must pick "PyroWave (wired LAN)"
in Settings (or PUNKTFUNK_PREFER_PYROWAVE=1); nothing changes for normal
HEVC/AV1 sessions. The Windows ARM64 client leg builds --no-default-features
and keeps skipping it (decode is Linux-native + Apple Metal today).

Advertisement no longer waits for the PUNKTFUNK_ENCODER=pyrowave lab
override on NVIDIA: host_wire_caps sets the bit whenever the feature is
present and the host isn't the GPU-less software pref, and
SessionPlan::output_format flips a PyroWave session on the NVIDIA-auto
capture path to CPU RGB frames (the EGL→CUDA import only NVENC consumes;
the wavelet backend ingests raw dmabufs or CPU RGB). AMD/Intel keep their
raw-dmabuf zero-copy unchanged; per-session raw-dmabuf passthrough on
NVIDIA (true zero-copy without the env's global capture policy) stays a
follow-up.

On-glass on .21 (RTX 5070 Ti, default-features binaries, NO env overrides):
host advertises + negotiates PyroWave, the CPU-capture fallback engages,
60 fps at e2e 3.2-5.7 ms p50, and a mid-stream 1080p→720p resize rides on
top cleanly. Workspace clippy --locked clean; 33 client + 314 host tests.

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

crates/punktfunk-host/Cargo.toml

@@ -251,6 +251,9 @@ pf-driver-proto = { path = "../pf-driver-proto" }
 bytemuck = { version = "1.19", features = ["derive"] }
 
 [features]
+# PyroWave ships in every default build (the codec stays strictly opt-in per session — a client
+# must explicitly prefer CODEC_PYROWAVE; nothing changes for normal HEVC/AV1 sessions).
+default = ["pyrowave"]
 # NVENC hardware encode (Windows). OFF by default (it pulls the NVENC SDK crate); nothing is
 # needed at link time — the entry points are resolved at RUNTIME from the driver's
 # nvEncodeAPI64.dll (encode/windows/nvenc.rs `load_api`), so the same binary starts fine on
@@ -269,9 +272,9 @@ amf-qsv = ["dep:ffmpeg-next"]
 # PUNKTFUNK_VULKAN_ENCODE (opt-in for now). Build the AMD/Intel RFI host with `--features vulkan-encode`.
 vulkan-encode = []
 # PyroWave — the opt-in wired-LAN intra-only wavelet codec (design/pyrowave-codec-plan.md).
-# Builds the vendored codec from source (crates/pyrowave-sys, CMake + bindgen; Linux/Windows).
-# OFF by default; runtime-gated further behind an explicit PUNKTFUNK_ENCODER=pyrowave.
-# EXPERIMENTAL until CODEC_PYROWAVE negotiation lands (plan Phase 2).
+# Builds the vendored codec from source (crates/pyrowave-sys, CMake + bindgen; Linux/Windows —
+# the encoder backend itself is Linux-only, the Windows host just carries the library). ON by
+# default (see `default` above); sessions reach it only through explicit client opt-in.
 pyrowave = ["dep:pyrowave-sys"]
 
 # Build-time icon/version-info embedding (build.rs; Windows dev/CI hosts only — Linux packaging