ci(rpm): publish punktfunk-host RPM to the Gitea registry (Bazzite)

Mirrors the apt pipeline for Fedora Atomic / Bazzite. New `rpm` workflow builds
the host RPM in a Fedora 43 builder image (ci/fedora-rpm.Dockerfile — matches
Bazzite's libavcodec.so.61, with a self-contained 16-symbol libcuda link stub so
no NVIDIA packages are needed in CI) and uploads to Gitea's public RPM registry
(group "bazzite") on every main push (rolling 0.0.1-0.ciN.<sha>) and v* tag
(clean X.Y.Z-1). Bazzite hosts then track it with `rpm-ostree upgrade`.

- packaging/rpm/build-rpm.sh: git-archive tarball + rpmbuild (--nodeps, since the
  toolchain is rustup + dnf, not RPMs); copies to dist/, asserts no cuda/nvidia leak.
- punktfunk.spec: overridable pf_version/pf_release for CI snapshots; exclude
  libcuda.so from auto-Requires (NVENC/EGL come from the driver, out of band) —
  same NVIDIA filter as the .deb; fix a bogus changelog weekday.
- docker.yml builds+pushes the new fedora-rpm image; packaging README + rpm/README
  document the rpm-ostree install/update path (recommended option).

Builder image seeded to the registry so rpm.yml's first run finds it. RPM build +
clean-Requires verified locally in the image (libavcodec.so.61 / libavutil.so.59,
no cuda).

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

packaging/rpm/punktfunk.spec

@@ -17,8 +17,12 @@
 ################################################################################
 
 Name:           punktfunk
-Version:        0.0.1
-Release:        1%{?dist}
+# Version/Release are overridable so CI can stamp a rolling snapshot: a main build passes
+#   --define "pf_version 0.0.1" --define "pf_release 0.ci42.gdeadbee"
+# (Release starting "0." sorts BEFORE the eventual "1" release), a v* tag passes the clean
+# version with "pf_release 1". A plain `rpmbuild` (or COPR) with no defines builds 0.0.1-1.
+Version:        %{?pf_version}%{!?pf_version:0.0.1}
+Release:        %{?pf_release}%{!?pf_release:1}%{?dist}
 Summary:        Low-latency desktop/game streaming host (Moonlight-compatible + punktfunk/1)
 
 License:        MIT OR Apache-2.0
@@ -29,6 +33,12 @@ Source0:        %{name}-%{version}.tar.gz
 # punktfunk-host is Linux-only and links system FFmpeg/PipeWire/Opus.
 ExclusiveArch:  x86_64 aarch64
 
+# The zerocopy FFI links the NVIDIA driver's libcuda.so.1; rpm's auto-dep generator would turn
+# that into a hard Requires on libcuda.so.1 (and we never want to pin the driver — NVENC/EGL come
+# from whatever NVIDIA stack the host runs, expressed below as the weak xorg-x11-drv-nvidia-cuda
+# Recommends). Drop it from the auto-Requires, mirroring the Debian package's NVIDIA filter.
+%global __requires_exclude ^libcuda\\.so.*$
+
 # --- Build toolchain ---------------------------------------------------------
 BuildRequires:  cargo
 BuildRequires:  rust
@@ -131,5 +141,5 @@ echo "then enable the host: systemctl --user enable --now punktfunk-host"
 echo "Config: cp %{_datadir}/%{name}/host.env.bazzite ~/.config/punktfunk/host.env"
 
 %changelog
-* Tue Jun 10 2026 punktfunk <noreply@anthropic.com> - 0.0.1-1
+* Wed Jun 10 2026 punktfunk <noreply@anthropic.com> - 0.0.1-1
 - Initial RPM: punktfunk-host + udev rule + systemd user unit + headless helpers.