feat(packaging/flatpak,decky): Steam Deck client flatpak + plugin deploy + CI

Ship the punktfunk Linux client to the Steam Deck as a Flatpak — the only viable SteamOS install path, since /usr is read-only and lacks libadwaita/SDL3 — and publish both it and the Decky plugin through Gitea. Built and validated live on a Steam Deck (SteamOS 3.7): bundle installs user-scope, all libs resolve, libavcodec resolves to the codecs-extra HEVC build, devices=all for DualSense hidraw. packaging/flatpak (new): - io.unom.Punktfunk.yml on GNOME 50 / freedesktop-sdk 25.08. rust-stable//25.08 (rustc 1.96 — the GTK4 chain needs >=1.92; the EOL GNOME-48/24.08 rust-stable at 1.89 could not build it) + llvm20 (libclang for bindgen in ffmpeg-sys-next/sdl3-sys). HEVC libavcodec comes from the runtime's auto codecs-extra extension point (no app-side codec declaration). Bundled SDL3 3.4.10 (matches sdl3-sys 0.6.6+SDL-3.4.10). finish-args: wayland/fallback-x11, --device=all (GPU/VAAPI + evdev + hidraw — flatpak cannot bind /dev/hidrawN char devices via --filesystem), pulseaudio, network, ~/.config/punktfunk. - metainfo.xml, desktop, square SVG icon, build-flatpak.sh (offline cargo-sources; on-Deck org.flatpak.Builder or CI), README. clients/decky: - add LICENSE (MIT), fix package.json license (BSD-3-Clause -> Apache-2.0 OR MIT), add scripts/{package.sh,deploy.sh} (the plugins dir is root-owned: stage to /tmp, sudo install, restart plugin_loader), align the launcher fallback to the real flatpak app id io.unom.Punktfunk, rewrite the install section. .gitea/workflows: - flatpak.yml: privileged Fedora container builds the bundle and publishes to the Gitea generic registry (+ release attachment on tags). - decky.yml: pnpm build -> store-layout zip -> registry (stable latest/ URL for Decky "install from URL"). docs: packaging/README + packaging/flatpak/README. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-15 01:43:35 +02:00
parent 79217eb93d
commit 8956bc14de
16 changed files with 882 additions and 19 deletions
@@ -0,0 +1,9 @@
+# Generated by flatpak-cargo-generator.py from Cargo.lock in CI (offline crate cache for the
+# manifest's punktfunk-client module). Regenerated on every build — never commit it.
+cargo-sources.json
+
+# flatpak-builder scratch / output (when building locally in this dir).
+.flatpak-builder/
+build-dir/
+repo/
+*.flatpak
@@ -0,0 +1,122 @@
+# punktfunk client — Flatpak (Steam Deck / SteamOS, and any flatpak distro)
+
+The native Linux **client** (crate `punktfunk-client-linux`, binary `punktfunk-client`) is
+published as a single-file **`.flatpak` bundle** to **Gitea's generic package registry** in
+the public `unom` org. CI (`.gitea/workflows/flatpak.yml`) builds and publishes on every push
+to `main` (a rolling `0.0.1-ciN.<sha>` build) and on `v*` tags (a clean `X.Y.Z`), and on tags
+also attaches the bundle to the Gitea release.
+
+> The **host** is NOT a flatpak (it needs unsandboxed `/dev/uinput` + zero-copy NVENC — see
+> [`../README.md`](../README.md) "Why not Flatpak"). Only the **client** is sandbox-friendly.
+
+## Why flatpak for the Steam Deck
+
+SteamOS `/usr` is read-only and image-based, and the system is **missing `libadwaita` and
+`libSDL3`** — so a bare `punktfunk-client` binary dropped into `~/.local/bin` won't run. Flatpak
+is the Deck's native, update-survivable app path (the user already runs Moonlight and chiaki-ng
+as flatpaks), and the bundle carries libadwaita (from `org.gnome.Platform//50`) + a bundled SDL3,
+with HEVC-capable FFmpeg supplied automatically by the runtime's `codecs-extra` extension.
+
+App id: **`io.unom.Punktfunk`** (matches the Apple bundle id family and the Decky plugin's
+flatpak fallback).
+
+## Install on the Deck (one-time)
+
+The generic registry is a plain HTTP file store, so just download the bundle and install it
+per-user (no root, survives SteamOS updates):
+
+```sh
+# Pick a version: a tag like 1.2.3, or the newest main build's 0.0.1-ciN.gSHA.
+VER=1.2.3
+URL="https://git.unom.io/api/packages/unom/generic/punktfunk-client-flatpak/$VER/punktfunk-client-$VER.flatpak"
+
+# Flathub must be enabled (it is on the Deck) so the GNOME runtime + ffmpeg-full pull in:
+flatpak remote-add --user --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
+
+curl -fL -o /tmp/punktfunk-client.flatpak "$URL"
+flatpak install --user --bundle /tmp/punktfunk-client.flatpak
+```
+
+Run it:
+
+```sh
+flatpak run io.unom.Punktfunk                 # GUI host list (mDNS)
+flatpak run io.unom.Punktfunk --connect HOST:PORT
+```
+
+The **Decky plugin** launches exactly this (`flatpak run io.unom.Punktfunk --connect …`) once
+installed — see [`../../clients/decky/README.md`](../../clients/decky/README.md).
+
+## Updates
+
+A bundle has no remote to track, so updates are "download the newer bundle and reinstall":
+
+```sh
+flatpak install --user --bundle /tmp/punktfunk-client.flatpak   # same command, newer file
+```
+
+(If you want `flatpak update` to track new builds automatically you'd need a hosted OSTree
+repo, which Gitea cannot serve — see "Alternatives" below. The bundle is the simplest path.)
+
+## Build locally / the CI fallback
+
+CI builds this in a **`--privileged`** Fedora container, because `flatpak-builder` runs
+`bubblewrap`, which needs user namespaces the default Docker executor denies. **If the Gitea
+runner can't grant `--privileged`** (the job fails at `flatpak-builder` with
+*"Creating new namespace failed: Operation not permitted"*), build it out-of-band and upload
+by hand. The easiest place is **on the Deck itself** (it can run `org.flatpak.Builder`
+user-scope, no root):
+
+```sh
+# On the Deck (or any flatpak box), one-time:
+flatpak install --user -y flathub org.flatpak.Builder
+
+# build-flatpak.sh auto-detects org.flatpak.Builder, generates cargo-sources.json (or reuses an
+# existing one — see below), builds, and exports dist/punktfunk-client-<version>.flatpak:
+bash packaging/flatpak/build-flatpak.sh
+
+# Upload to the generic registry (PAT with write:package):
+curl -fsS --user "enricobuehler:$REGISTRY_TOKEN" \
+  --upload-file dist/punktfunk-client-*.flatpak \
+  "https://git.unom.io/api/packages/unom/generic/punktfunk-client-flatpak/0.0.1-manual/punktfunk-client.flatpak"
+```
+
+> `cargo-sources.json` generation needs `python3` + `aiohttp` + `tomlkit`, which the Deck lacks.
+> Generate it on a dev box (`build-flatpak.sh` does it, or run the upstream
+> `flatpak-cargo-generator.py Cargo.lock -o packaging/flatpak/cargo-sources.json`), rsync it next
+> to the manifest, and `build-flatpak.sh` reuses it (it only regenerates when the file is absent
+> or `FORCE_GEN=1`).
+
+> The Mac build host **cannot** build a Linux flatpak (no flatpak-builder for macOS), and
+> home-worker-2 has no flatpak and no passwordless sudo to install it — so the Deck or the
+> privileged CI container are the only two viable build sites.
+
+## Manifest
+
+[`io.unom.Punktfunk.yml`](io.unom.Punktfunk.yml). Runtime `org.gnome.Platform//50`
+(GTK 4.20 + libadwaita 1.8 ≥ the crate floors of v4_16 / v1_5), built on freedesktop-sdk 25.08,
+with two build-time SDK extensions: `org.freedesktop.Sdk.Extension.rust-stable` (→ //25.08,
+**rustc 1.96** — the GTK4 dep chain, e.g. pango-sys 0.22, needs ≥ 1.92, which the EOL GNOME-48 /
+24.08 rust-stable at 1.89 could not provide) and `org.freedesktop.Sdk.Extension.llvm20` (libclang,
+needed by bindgen in ffmpeg-sys-next / sdl3-sys). HEVC-capable libavcodec (soname 61, accepted by
+ffmpeg-next 8.x) is supplied **automatically at runtime** by the freedesktop `codecs-extra`
+extension point (auto-downloaded with the runtime; no app-side codec declaration). A bundled
+**SDL3 3.4.10** module (pinned to match `sdl3-sys 0.6.6+SDL-3.4.10`), and finish-args for Wayland +
+`--device=all` (GPU/VAAPI render node + evdev + the hidraw char-devices SDL3 needs for DualSense)
+ `--socket=pulseaudio` (PipeWire-pulse: playback + mic) + `--share=network`. Alongside it:
+`io.unom.Punktfunk.desktop`, `io.unom.Punktfunk.metainfo.xml`, `io.unom.Punktfunk.svg` (all
+installed by the manifest). `cargo-sources.json` (the offline crate cache) is a pure function of
+`Cargo.lock`; CI regenerates it each build and it is **gitignored** — generate it on any box with
+network + `python3`/`aiohttp`/`tomlkit` (`build-flatpak.sh` does this automatically) and, for a
+build host that lacks those (the Deck), rsync the generated file in alongside the manifest.
+
+## Alternatives considered (and why the bundle wins)
+
+- **Generic registry bundle (chosen):** one curl to publish, one `flatpak install --bundle` to
+  consume; mirrors the existing deb/rpm curl-upload pattern exactly. No auto-update.
+- **Release attachment:** also done on tags (the bundle is attached to the Gitea release), good
+  for a human-facing download page; the generic registry gives the stable per-version URL the
+  Decky fallback and scripts use.
+- **Self-hosted OSTree repo (rejected):** would enable `flatpak update`, but Gitea has no
+  flatpak/ostree registry, so it would mean serving a static OSTree tree over Gitea raw/Pages —
+  more moving parts than the appliance needs today.
@@ -0,0 +1,85 @@
+#!/usr/bin/env bash
+# Build the punktfunk Linux client as a single-file `.flatpak` bundle.
+#
+# Works on the Steam Deck (org.flatpak.Builder from Flathub, user-scope, NO root) and on any
+# Linux box with flatpak + flatpak-builder. The CI does the same steps (.gitea/workflows/flatpak.yml).
+#
+# On the Deck (one-time):
+#   flatpak install --user -y flathub org.flatpak.Builder
+# Then run this script from the repo root:
+#   bash packaging/flatpak/build-flatpak.sh
+# Output: dist/punktfunk-client-<version>.flatpak  (install with `flatpak install --user <file>`)
+#
+# Env knobs:
+#   VERSION=...        version string for the bundle name (default: git describe / 0.0.1-dev)
+#   ONLINE=1           skip offline cargo-sources.json; build with --share=network (fast local
+#                      iteration, non-reproducible). Default: offline (regenerates cargo-sources).
+#   BUILDER=...        override the flatpak-builder invocation (default: auto-detect host
+#                      flatpak-builder, else `flatpak run org.flatpak.Builder`).
+set -euo pipefail
+
+ROOTDIR="$(cd "$(dirname "$0")/../.." && pwd)"
+cd "$ROOTDIR"
+
+APP_ID="io.unom.Punktfunk"
+MANIFEST="packaging/flatpak/io.unom.Punktfunk.yml"
+VERSION="${VERSION:-$(git describe --tags --always --dirty 2>/dev/null || echo 0.0.1-dev)}"
+VERSION="${VERSION#v}"
+BUNDLE="dist/punktfunk-client-${VERSION}.flatpak"
+
+# --- pick a flatpak-builder (host binary, or the org.flatpak.Builder flatpak on the Deck) ---
+if [ -n "${BUILDER:-}" ]; then
+  FPB=($BUILDER)
+elif command -v flatpak-builder >/dev/null 2>&1; then
+  FPB=(flatpak-builder)
+elif flatpak info org.flatpak.Builder >/dev/null 2>&1; then
+  FPB=(flatpak run org.flatpak.Builder)
+else
+  echo "error: need flatpak-builder. On the Deck: flatpak install --user -y flathub org.flatpak.Builder" >&2
+  exit 1
+fi
+
+# --- ensure Flathub is available for the runtime/SDK/extensions ---
+flatpak remote-add --user --if-not-exists flathub \
+  https://dl.flathub.org/repo/flathub.flatpakrepo
+
+# --- offline crate cache (skip with ONLINE=1) -------------------------------------------
+EXTRA_ARGS=()
+if [ "${ONLINE:-0}" = "1" ]; then
+  echo "==> ONLINE build (cargo fetches from crates.io; non-reproducible)"
+  EXTRA_ARGS+=(--build-args=--share=network)
+  # The manifest references cargo-sources.json; provide an empty list so it stays valid.
+  [ -f packaging/flatpak/cargo-sources.json ] || echo '[]' > packaging/flatpak/cargo-sources.json
+elif [ -f packaging/flatpak/cargo-sources.json ] && [ "${FORCE_GEN:-0}" != "1" ]; then
+  # Reuse a cargo-sources.json that was generated elsewhere (e.g. on a dev box with network +
+  # python aiohttp/toml, then rsynced to a build host that lacks them — like the Deck). The
+  # offline crate cache is a pure function of Cargo.lock, so this is reproducible. FORCE_GEN=1
+  # to regenerate anyway.
+  echo "==> reusing existing packaging/flatpak/cargo-sources.json (FORCE_GEN=1 to regenerate)"
+else
+  echo "==> generating offline cargo-sources.json from Cargo.lock"
+  GEN=/tmp/flatpak-cargo-generator.py
+  if [ ! -f "$GEN" ]; then
+    curl -fsSL -o "$GEN" \
+      https://raw.githubusercontent.com/flatpak/flatpak-builder-tools/master/cargo/flatpak-cargo-generator.py
+  fi
+  # Needs python3 + aiohttp + toml. On a host that lacks them (e.g. the Deck), generate on the
+  # Mac / a dev box instead and rsync the result next to the manifest (reused by the branch above).
+  python3 "$GEN" Cargo.lock -o packaging/flatpak/cargo-sources.json
+fi
+
+# --- build into a local ostree repo, then export a single-file bundle --------------------
+echo "==> flatpak-builder ($APP_ID, version $VERSION)"
+"${FPB[@]}" --user --force-clean --disable-rofiles-fuse \
+  --install-deps-from=flathub \
+  "${EXTRA_ARGS[@]}" \
+  --repo="$ROOTDIR/.flatpak-repo" \
+  "$ROOTDIR/.flatpak-build" "$MANIFEST"
+
+mkdir -p dist
+flatpak build-bundle "$ROOTDIR/.flatpak-repo" "$BUNDLE" "$APP_ID"
+echo "built $BUNDLE"
+ls -lh "$BUNDLE"
+echo
+echo "install:  flatpak install --user -y $BUNDLE"
+echo "run:      flatpak run $APP_ID            (or:  flatpak run $APP_ID --connect host:port)"
@@ -0,0 +1,10 @@
+[Desktop Entry]
+Type=Application
+Name=Punktfunk
+Comment=Stream a remote punktfunk host
+Exec=punktfunk-client
+Icon=io.unom.Punktfunk
+Terminal=false
+Categories=Network;Game;
+Keywords=streaming;remote;game;moonlight;
+StartupNotify=true
@@ -0,0 +1,68 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- AppStream metainfo for the punktfunk Linux client flatpak. Validate with:
+       appstreamcli validate packaging/flatpak/io.unom.Punktfunk.metainfo.xml
+     The component id MUST equal the flatpak app-id; the <launchable> MUST name the installed
+     desktop file (io.unom.Punktfunk.desktop). -->
+<component type="desktop-application">
+  <id>io.unom.Punktfunk</id>
+  <metadata_license>CC0-1.0</metadata_license>
+  <project_license>MIT OR Apache-2.0</project_license>
+  <name>Punktfunk</name>
+  <summary>Low-latency desktop and game streaming client</summary>
+
+  <description>
+    <p>
+      Punktfunk is the native Linux client for the punktfunk low-latency desktop and game
+      streaming stack. It discovers hosts on the LAN over mDNS, trusts them via certificate
+      pinning with a SPAKE2 PIN pairing ceremony, and streams HEVC video (GF(2^16) Leopard
+      FEC plus AES-GCM over UDP, with a QUIC control plane) at exactly the requested
+      resolution and refresh rate — no scaling.
+    </p>
+    <p>Features:</p>
+    <ul>
+      <li>Hardware-accelerated HEVC decode (VAAPI zero-copy on AMD and Intel, software fallback)</li>
+      <li>PipeWire audio playback and microphone uplink</li>
+      <li>Full gamepad support including DualSense touchpad, motion, adaptive triggers and lightbar (SDL3)</li>
+      <li>LAN host discovery, TOFU fingerprint pinning and PIN pairing</li>
+    </ul>
+  </description>
+
+  <launchable type="desktop-id">io.unom.Punktfunk.desktop</launchable>
+
+  <categories>
+    <category>Network</category>
+    <category>Game</category>
+    <category>RemoteAccess</category>
+  </categories>
+
+  <keywords>
+    <keyword>streaming</keyword>
+    <keyword>remote</keyword>
+    <keyword>game</keyword>
+    <keyword>moonlight</keyword>
+  </keywords>
+
+  <url type="homepage">https://git.unom.io/unom/punktfunk</url>
+  <url type="bugtracker">https://git.unom.io/unom/punktfunk/issues</url>
+  <url type="vcs-browser">https://git.unom.io/unom/punktfunk</url>
+
+  <developer id="io.unom">
+    <name>unom</name>
+  </developer>
+
+  <content_rating type="oars-1.1"/>
+
+  <branding>
+    <color type="primary" scheme_preference="light">#a79ff8</color>
+    <color type="primary" scheme_preference="dark">#6c5bf3</color>
+  </branding>
+
+  <!-- Bump on each release; the version/date should track the published bundle. -->
+  <releases>
+    <release version="0.0.1" date="2026-06-15">
+      <description>
+        <p>Initial flatpak packaging of the native Linux client for the Steam Deck and Wayland desktops.</p>
+      </description>
+    </release>
+  </releases>
+</component>
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg width="1000" height="1000" viewBox="0 0 1000 1000" version="1.1"
+     xmlns="http://www.w3.org/2000/svg"
+     style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:2;">
+  <!-- Brand mark: three overlapping circles (flattened from clients/apple punktfunk_Logo.icon).
+       Order back-to-front: large violet circle (layer 1), deep-purple circle (layer 2),
+       light lens highlight (layer 3). -->
+  <rect x="0" y="0" width="1000" height="1000" rx="180" ry="180" fill="#1c1530"/>
+  <path d="M403.037,791.672c107.586,0 194.41,-86.824 194.41,-194.41c0,-107.586 -86.824,-194.41 -194.41,-194.41c-107.586,0 -194.41,86.824 -194.41,194.41c0,107.586 86.824,194.41 194.41,194.41Z" fill="#a79ff8"/>
+  <path d="M735.276,540.321c76.075,-76.075 76.075,-198.862 0,-274.937c-76.075,-76.075 -198.862,-76.075 -274.937,0c-76.075,76.075 -76.075,198.862 0,274.937c76.075,76.075 198.862,76.075 274.937,0Z" fill="#6c5bf3"/>
+  <path d="M647.84,590.737c-64.853,17.403 -136.871,0.597 -187.885,-50.416c-51.013,-51.013 -67.819,-123.032 -50.416,-187.885c64.853,-17.403 136.871,-0.597 187.885,50.416c51.013,51.013 67.819,123.032 50.416,187.885Z" fill="#d2c9fb"/>
+</svg>
@@ -0,0 +1,159 @@
+# Flatpak manifest for the native punktfunk Linux client (crate punktfunk-client-linux,
+# binary `punktfunk-client`). Built into a single-file `.flatpak` bundle and published to
+# Gitea's generic package registry (see .gitea/workflows/flatpak.yml + packaging/flatpak/README.md).
+#
+# Why flatpak for the CLIENT (the host stays an RPM/deb — see packaging/README.md "Why not
+# Flatpak"): on SteamOS the Steam Deck's /usr is read-only and image-based, so a bare
+# `punktfunk-client` binary in ~/.local/bin can't bring its own libadwaita / SDL3 (both
+# MISSING from the SteamOS system) — but flatpak is the Deck's native, update-survivable app
+# path (the user already runs Moonlight + chiaki-ng as flatpaks). Unlike the host, the client
+# is sandbox-friendly: it only needs the GPU render node, the host PipeWire socket, the
+# network, Wayland, hidraw for DualSense, and its config dir — all expressible as finish-args.
+#
+# Runtime: GNOME 50 ships GTK 4.20 and libadwaita 1.8 — both far exceed the crate floors
+# (gtk4 0.11 "v4_16", libadwaita 0.9 "v1_5"). GNOME 50 is built on freedesktop-sdk 25.08, so
+# `org.freedesktop.Sdk.Extension.rust-stable` resolves to //25.08 (rustc 1.96 — the GTK4 dep
+# chain, e.g. pango-sys 0.22, needs >= 1.92, which the older GNOME-48/24.08 rust-stable at 1.89
+# could NOT satisfy). GNOME 50 is also a *supported* runtime (GNOME 48 went EOL in March 2026).
+# libopus and the PipeWire client lib are in the freedesktop base; SDL3 is NOT, so it is built
+# from source as a bundled module.
+#
+# HEVC decode: the base runtime's libavcodec is a stripped build (no encumbered codecs). The
+# freedesktop runtime declares `org.freedesktop.Platform.codecs-extra` as a built-in extension
+# point (directory lib/x86_64-linux-gnu/codecs-extra, add-ld-path lib, auto-downloaded with the
+# runtime), whose full libavcodec.so.61 transparently shadows the base one at runtime. So HEVC
+# (software + VAAPI) works with NO app-side codec extension to declare — we just build against
+# the SDK's linkable libavcodec.so.61 and let the runtime swap in the capable build.
+app-id: io.unom.Punktfunk
+runtime: org.gnome.Platform
+runtime-version: '50'
+sdk: org.gnome.Sdk
+# Build-time SDK extensions:
+#  - rust-stable: cargo/rustc 1.96 + the bundled mold linker (/usr/lib/sdk/rust-stable/bin).
+#  - llvm20: provides libclang (/usr/lib/sdk/llvm20/lib), which bindgen needs — ffmpeg-sys-next
+#    and sdl3-sys generate their FFI bindings via bindgen at build time. The base SDK ships no
+#    clang/libclang, so without this the build panics ("Unable to find libclang").
+# Both are added to PATH / LIBCLANG_PATH in build-options below.
+sdk-extensions:
+  - org.freedesktop.Sdk.Extension.rust-stable
+  - org.freedesktop.Sdk.Extension.llvm20
+command: punktfunk-client
+
+cleanup:
+  - /include
+  - /lib/pkgconfig
+  - /lib/cmake
+  - /share/aclocal
+  - /man
+  - /share/man
+  - '*.a'
+  - '*.la'
+
+finish-args:
+  # --- display ---
+  - --socket=wayland                 # GTK4 native Wayland window (the client is Wayland-first)
+  - --socket=fallback-x11            # Xwayland fallback when no Wayland socket is exposed
+  - --share=ipc                      # required alongside X11 for shared-memory surfaces
+  # --- GPU + all input devices ---
+  # --device=all (not just --device=dri): covers the GPU render node (VAAPI HEVC decode + GL),
+  # evdev joysticks, AND the hidraw CHAR devices SDL3's HIDAPI needs for DualSense touchpad/
+  # motion/adaptive-triggers/lightbar. flatpak cannot bind individual /dev/hidrawN via
+  # --filesystem (they are char devices — "unsupported type 0o20000"), and there is no granular
+  # --device=hidraw; --device=all is what game/emulator flatpaks (RetroArch, Dolphin) use. We
+  # self-host via the Gitea generic registry — NOT Flathub — so its --device=all review rule
+  # does not apply.
+  - --device=all
+  - --filesystem=/run/udev:ro        # SDL/HIDAPI enumerates devices via udev
+  # --- audio: PipeWire via its PulseAudio shim — covers playback AND mic uplink. SteamOS
+  #     exposes PipeWire-pulse here; --socket=pulseaudio is the portable arg Moonlight/chiaki
+  #     also use on the Deck (a bare --socket=pipewire would also need the camera/portal dance
+  #     for capture; the pulse shim gives mic + speaker in one grant). ---
+  - --socket=pulseaudio
+  # --- network: QUIC control + UDP data plane + mDNS discovery (_punktfunk._udp) ---
+  - --share=network
+  # --- persistent client identity / pairing store (shared with punktfunk-client-rs) ---
+  - --filesystem=~/.config/punktfunk:create   # client-{cert,key}.pem, known-hosts, settings
+
+build-options:
+  append-path: /usr/lib/sdk/rust-stable/bin:/usr/lib/sdk/llvm20/bin
+  # The rust build resolves everything via pkg-config: gtk4/libadwaita/pipewire/opus AND a
+  # linkable libavcodec.so.61 from org.gnome.Sdk//50 (the multiarch /usr dir), plus the bundled
+  # SDL3's .pc from /app. (At runtime the codecs-extra extension swaps in the HEVC-capable
+  # libavcodec — see the header.)
+  env:
+    PKG_CONFIG_PATH: /app/lib/pkgconfig:/usr/lib/x86_64-linux-gnu/pkgconfig:/usr/lib/pkgconfig
+    # bindgen (ffmpeg-sys-next / sdl3-sys) loads libclang from the llvm20 extension.
+    LIBCLANG_PATH: /usr/lib/sdk/llvm20/lib
+    # mold (shipped in rust-stable) speeds the ~450-crate link on the Deck APU.
+    RUSTFLAGS: -C link-arg=-fuse-ld=mold
+
+modules:
+  # ---------------------------------------------------------------------------------------
+  # SDL3 — NOT provided as a linkable libSDL3.so.0 by org.gnome.Platform/freedesktop-sdk
+  # 25.08, and there is no SDL3 recipe in flathub/shared-modules. Build it from source.
+  # Pinned to 3.4.10 to match the crate exactly: sdl3-sys is `0.6.6+SDL-3.4.10`, i.e. its
+  # bindings target SDL 3.4.10 — building an older SDL risks missing symbols at link time.
+  # HIDAPI is enabled (DualSense touchpad/motion/triggers/lightbar over hidraw).
+  # ---------------------------------------------------------------------------------------
+  - name: sdl3
+    buildsystem: cmake-ninja
+    config-opts:
+      - -DCMAKE_BUILD_TYPE=Release
+      - -DSDL_SHARED=ON
+      - -DSDL_STATIC=OFF
+      - -DSDL_HIDAPI=ON          # DualSense full fidelity over hidraw
+      - -DSDL_TEST_LIBRARY=OFF
+      - -DSDL_EXAMPLES=OFF
+    sources:
+      - type: archive
+        url: https://github.com/libsdl-org/SDL/releases/download/release-3.4.10/SDL3-3.4.10.tar.gz
+        # `sha256sum SDL3-3.4.10.tar.gz` (verified 2026-06-15). Bump url + sha together.
+        sha256: 12b34280415ec8418c864408b93d008a20a6530687ee613d60bfbd20411f2785
+        x-checker-data:
+          type: anitya
+          project-id: 4974
+          stable-only: true
+          url-template: https://github.com/libsdl-org/SDL/releases/download/release-$version/SDL3-$version.tar.gz
+    cleanup:
+      - /bin
+      - /include
+      - /lib/cmake
+      - /lib/pkgconfig
+
+  # ---------------------------------------------------------------------------------------
+  # The client. cargo-sources.json is the GENERATED offline crate cache:
+  #   python3 flatpak-cargo-generator.py Cargo.lock -o packaging/flatpak/cargo-sources.json
+  # (run from the repo root; the CI step does exactly this). With it present the build is fully
+  # offline (CARGO_NET_OFFLINE). For quick LOCAL iteration WITHOUT regenerating it, drop the
+  # cargo-sources.json source and pass  --build-args=--share=network  to flatpak-builder
+  # (non-reproducible; cargo fetches from crates.io during the build).
+  # ---------------------------------------------------------------------------------------
+  - name: punktfunk-client
+    buildsystem: simple
+    build-options:
+      env:
+        CARGO_HOME: /run/build/punktfunk-client/cargo
+        CARGO_NET_OFFLINE: 'true'
+    build-commands:
+      - cargo --offline build --release --locked -p punktfunk-client-linux
+      - install -Dm0755 target/release/punktfunk-client ${FLATPAK_DEST}/bin/punktfunk-client
+      # Desktop entry (renamed to the app id; Exec is the in-sandbox binary).
+      - install -Dm0644 packaging/flatpak/io.unom.Punktfunk.desktop
+          ${FLATPAK_DEST}/share/applications/io.unom.Punktfunk.desktop
+      # AppStream metainfo (required for a well-formed flatpak / Software listings).
+      - install -Dm0644 packaging/flatpak/io.unom.Punktfunk.metainfo.xml
+          ${FLATPAK_DEST}/share/metainfo/io.unom.Punktfunk.metainfo.xml
+      # Scalable icon named for the app id (GNOME runtime renders SVG via librsvg).
+      - install -Dm0644 packaging/flatpak/io.unom.Punktfunk.svg
+          ${FLATPAK_DEST}/share/icons/hicolor/scalable/apps/io.unom.Punktfunk.svg
+    sources:
+      # The repo checkout. For a Flathub/published build, replace with a pinned git source:
+      #   - type: git
+      #     url: https://git.unom.io/unom/punktfunk
+      #     tag: vX.Y.Z
+      #     commit: <sha>
+      # For ON-DECK / CI builds we build the checked-out working tree in place:
+      - type: dir
+        path: ../..
+      # Generated offline crate cache (see the comment block above). Remove for --share=network.
+      - cargo-sources.json