refactor(host/W6.2): extract the video encode backends into the pf-encode crate

encode.rs + encode/* (NVENC, VAAPI, native AMF, AMF/QSV ffmpeg, direct-SDK
NVENC/CUDA, raw Vulkan-Video, PyroWave, openh264) move into crates/pf-encode
behind one Encoder trait + open_video selector (plan §W6). The crate speaks the
shared frame vocabulary (pf-frame: CapturedFrame/PixelFormat + the DXGI identity
D3d11Frame/make_device) and pf-zerocopy (CUDA context/buffers), and NEVER
pf-capture — the capture→encode edge is one-way (ZeroCopyPolicy, prior commit).

Dep moves: the heavy encoder deps (ffmpeg-next, the NVENC SDK, openh264,
pyrowave-sys) move from the host to pf-encode; the host's
nvenc/amf-qsv/vulkan-encode/pyrowave features now FORWARD to pf-encode/*. The
host keeps a mod-encode shim (pub use pf_encode) so every crate::encode::* path
(negotiator + GameStream/native/mgmt planes) is unchanged.

resolve_render_adapter_luid moves from the host's windows/win_adapter.rs into
pf-gpu (both pf-encode and pf-capture need it as a peer of GPU selection); its 5
call sites (encode amf/nvenc, capture idd_push/synthetic_nv12, vdisplay manager)
rewire to pf_gpu::resolve_render_adapter_luid and win_adapter.rs is deleted.
pf-frame's make_device gains a # Safety section (public-unsafe-fn lint, latent
since the pf-frame carve — a full-workspace -D warnings clippy catches it).

Verified: Linux clippy -D warnings (pf-encode + host nvenc,vulkan-encode,pyrowave
--all-targets) + 13/13 pf-encode + 299/299 host tests; Windows clippy -D warnings
(pf-encode nvenc,amf-qsv --all-targets + host nvenc,amf-qsv --all-targets)
Finished exit 0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -2799,6 +2799,28 @@ dependencies = [
  "bytemuck",
 ]
 
+[[package]]
+name = "pf-encode"
+version = "0.12.0"
+dependencies = [
+ "anyhow",
+ "ash",
+ "ffmpeg-next",
+ "libc",
+ "libloading",
+ "nvidia-video-codec-sdk",
+ "openh264",
+ "pf-frame",
+ "pf-gpu",
+ "pf-host-config",
+ "pf-zerocopy",
+ "punktfunk-core",
+ "pyrowave-sys",
+ "tracing",
+ "tracing-subscriber",
+ "windows 0.62.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "pf-ffvk"
 version = "0.12.0"
@@ -3166,7 +3188,6 @@ dependencies = [
  "base64",
  "bytemuck",
  "cbc",
- "ffmpeg-next",
  "futures-util",
  "hex",
  "hmac",
@@ -3180,11 +3201,10 @@ dependencies = [
  "log",
  "mac_address",
  "mdns-sd",
- "nvidia-video-codec-sdk",
- "openh264",
  "opus",
  "parking_lot",
  "pf-driver-proto",
+ "pf-encode",
  "pf-frame",
  "pf-gpu",
  "pf-host-config",
@@ -3193,7 +3213,6 @@ dependencies = [
  "pf-zerocopy",
  "pipewire",
  "punktfunk-core",
- "pyrowave-sys",
  "quinn",
  "rand 0.8.6",
  "rcgen",