feat(host): VAAPI codec probe + AMD/Intel packaging + neutral logs (Phase 3)

Polish for AMD/Intel support:
- GameStream serverinfo advertises only codecs the GPU can ACTUALLY encode on
  the VAAPI backend (probed once by opening a tiny encoder per codec). AV1
  encode is narrow (Intel Arc/Xe2+, AMD RDNA3+/RDNA4) and an old iGPU may lack
  HEVC, so a Moonlight client never negotiates a codec the encoder can't open.
  NVENC/Windows keep the Moonlight-validated static mask. Validated on a Radeon
  780M: h264/h265/av1 all probe true -> mask unchanged (65793).
- Packaging: Recommends mesa-va-drivers + intel-media-va-driver (deb) /
  mesa-va-drivers + intel-media-driver (rpm) so the auto-selected VAAPI backend
  works out of the box on AMD/Intel; NVIDIA boxes can --no-install-recommends.
  (Fedora note: stock mesa-va-drivers disables HEVC/AV1 -- needs the freeworld
  variant from RPM Fusion.)
- De-NVIDIA-fy the user-facing encoder log/context strings ("open NVENC" ->
  "open video encoder") now that VAAPI is a first-class backend.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

packaging/rpm/punktfunk.spec

@@ -100,6 +100,11 @@ Suggests:       kwin
 Suggests:       mutter
 # NVENC + GPU EGL come from the NVIDIA driver; on Bazzite the -nvidia image has it.
 Recommends:     (xorg-x11-drv-nvidia-cuda if xorg-x11-drv-nvidia)
+# VAAPI encode drivers for AMD (radeonsi) / Intel (iHD) — the auto-selected VAAPI backend on a
+# non-NVIDIA GPU. NOTE: Fedora's stock mesa-va-drivers has HEVC/AV1 *disabled* (patents); full
+# encode needs mesa-va-drivers-freeworld from RPM Fusion (same nonfree repo as ffmpeg-libs).
+Recommends:     mesa-va-drivers
+Recommends:     intel-media-driver
 # The management web console (pairing + status) every user needs — a separate noarch subpackage.
 # Weak-dep so `dnf install punktfunk` pulls it where it exists (the Gitea registry); harmless where
 # it doesn't (a COPR build without `--with web` simply has no punktfunk-web to satisfy).