ci(linux): check the runner's libraries reach the package metadata

The plane added three runtime libraries that bundle-libs.sh deliberately does not
bundle, so they have to be declared per distro by hand - and two hand-maintained
lists drifting apart is the failure this guard exists to prevent.

check_linux_package_deps.py parses the runner's CMake for every pkg-config module
it links, follows target_link_libraries to prove each one actually reaches the
binary, and requires a package name for it in every distro's depends list. It
fails closed on the shapes a naive parser gets wrong: a pkg_check_modules call
naming several modules, options preceding the module name, and version
constraints like mpv>=0.40 that would otherwise be read as a package nobody
ships.

The smoke job builds the three packages and reads the dependencies back out of
the artifacts, deriving what to expect from build-packages.py rather than
restating it - so a library is declared once and verified everywhere. That job is
off by default, which is exactly why it must not carry its own copy of the list.

The Linux native job names libwayland-dev and libegl-dev instead of riding
GTK's and epoxy's transitive dev dependencies, matching the CMake comment's own
rationale. In CI the host-dependency guard runs once: the named step covers the
staged bundle, and build-packages.py's internal run - which exists for by-hand
packaging - is skipped. The smoke job also drops patchelf, which nothing
invokes.

.github/workflows/ci.yml

@@ -9,6 +9,14 @@ on:
     branches:
       - main
   workflow_dispatch:
+    inputs:
+      build_linux_packages:
+        description: >
+          Smoke-build the Linux deb/rpm/pacman packages. Off by default: it needs
+          a release build plus fpm, and build.yml only packages from main, so this
+          is the only way to exercise linux/packaging from a branch.
+        default: false
+        type: boolean
 
 env:
   # Only place this workflow names the SDK; .github/actions/setup-flutter-git pins the same release.
@@ -244,7 +252,7 @@ jobs:
       - name: Verify native formatting
         run: scripts/format_native.sh --check
 
-      - name: Verify Linux native acquisition integrity
+      - name: Verify Linux native acquisition and build plan
         run: bash linux/packaging/build-libmpv_test.sh
 
   linux-native-test:
@@ -279,7 +287,8 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
             clang cmake ninja-build pkg-config libgtk-3-dev liblzma-dev \
-            libstdc++-12-dev libmpv-dev libepoxy-dev libcurl4-openssl-dev libevdev-dev
+            libstdc++-12-dev libmpv-dev libepoxy-dev libcurl4-openssl-dev libevdev-dev \
+            libwayland-dev libegl-dev
 
       - name: Prepare Flutter Linux configuration
         run: |
@@ -295,13 +304,20 @@ jobs:
             -DPLEZY_BUILD_MPV_RELIABILITY_TESTS=ON \
             -DPLEZY_MPV_RELIABILITY_SANITIZER=${{ matrix.sanitizer }}
 
+      # `plezy` is the runner itself. Without it nothing in CI ever compiles
+      # my_application.cc, mpv_plugin.cc or the Wayland video plane — the
+      # reliability test targets each pull in only a couple of translation units,
+      # so a break in the rest of linux/runner reached a release build unseen.
       - name: Build Linux native reliability tests
         run: |
           cmake --build build/linux-native-${{ matrix.sanitizer }} --parallel 2 --target \
+            plezy \
             mpv_player_lifecycle_test \
+            mpv_player_hdr_output_test \
             mpv_property_result_contract_test \
             hdr_metadata_test \
-            plane_geometry_test
+            plane_geometry_test \
+            video_params_test
 
       - name: Run Linux native reliability tests
         run: |
@@ -593,3 +609,154 @@ jobs:
 
       - name: Run website checks
         run: scripts/ci_website_checks.sh
+
+
+  # The only job that checks packaging against a real artifact. build.yml also
+  # packages Linux, but refuses any ref but refs/heads/main, and
+  # check_linux_package_deps.py can only compare a hand-written list against
+  # CMake - it cannot prove the list reaches the artifact, nor see the
+  # transitive libraries the bundled libmpv drags in. This can, by reading the
+  # built bundle back with ldd.
+  #
+  # Runs on every push to main and on request, but not on pull requests: it
+  # needs a release build plus fpm, which is minutes of runner time that most
+  # changes here have no reason to pay. That buys post-merge detection rather
+  # than pre-merge, which is the deliberate trade. Dispatch it from a branch
+  # with build_linux_packages when touching linux/packaging - which is the only
+  # way to exercise it before merging.
+  linux-packages:
+    name: Linux package smoke build
+    if: ${{ inputs.build_linux_packages || github.event_name == 'push' }}
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+        with:
+          persist-credentials: false
+
+      - name: Setup Flutter
+        uses: subosito/flutter-action@1a449444c387b1966244ae4d4f8c696479add0b2 # v2
+        with:
+          channel: "stable"
+          flutter-version: ${{ env.FLUTTER_VERSION }}
+          cache: true
+          pub-cache: false
+
+      # The packaging deps, minus libmpv: this job builds it from source below,
+      # because the distro's is a different version with different windowing
+      # backends, and a package smoke-built against it cannot show that
+      # build-libmpv.sh still works or that the bundle it produces is coherent.
+      - name: Install packaging dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            clang cmake meson ninja-build pkg-config nasm libgtk-3-dev liblzma-dev \
+            libstdc++-12-dev libepoxy-dev libcurl4-openssl-dev libevdev-dev \
+            libasound2-dev libass-dev libfreetype-dev libfontconfig-dev libfribidi-dev \
+            libharfbuzz-dev libegl-dev libgl-dev libgnutls28-dev libpipewire-0.3-dev \
+            libva-dev libxkbcommon-dev libpulse-dev libdbus-1-dev libdrm-dev \
+            libgbm-dev libwayland-dev wayland-protocols liblcms2-dev libmujs-dev \
+            liblua5.2-dev rpm libarchive-tools imagemagick ruby-dev build-essential
+          sudo gem install fpm --version 1.17.0 --no-document
+
+      # Keyed the same way build.yml keys it, so editing the script or its pinned
+      # inputs is what invalidates the cache - and this branch's whole point is
+      # that those edits get exercised somewhere.
+      - name: Cache libmpv build
+        id: libmpv-cache
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
+        with:
+          path: libmpv-prefix
+          key: ci-libmpv-${{ runner.arch }}-${{ hashFiles('linux/packaging/build-libmpv.sh', 'linux/packaging/native-inputs.json') }}
+
+      - name: Build libmpv
+        if: steps.libmpv-cache.outputs.cache-hit != 'true'
+        run: bash linux/packaging/build-libmpv.sh
+
+      # The windowing backends the runner depends on, read off the library the
+      # script just produced. The plane hands mpv MPV_RENDER_PARAM_WL_DISPLAY, so
+      # a libmpv without Wayland cannot find the VAAPI device and quietly decodes
+      # in software; X11 and VDPAU are gone with the texture path.
+      - name: Check the built libmpv's backends
+        run: |
+          LIB=$(find libmpv-prefix -name 'libmpv.so.2' | head -1)
+          echo "== $LIB =="
+          ldd "$LIB" | grep -iE 'wayland|libX11|vdpau' || echo '(none)'
+          ldd "$LIB" | grep -q libwayland-client || {
+            echo "::error::the built libmpv does not link libwayland-client, so the video plane cannot work"
+            exit 1
+          }
+
+      - name: Build the release bundle
+        run: |
+          flutter pub get --enforce-lockfile --no-example
+          flutter build linux --release
+        env:
+          PKG_CONFIG_PATH: ${{ github.workspace }}/libmpv-prefix/lib/pkgconfig:${{ github.workspace }}/libmpv-prefix/lib/x86_64-linux-gnu/pkgconfig
+
+      # Mirrors build.yml: resolve the bundle completely, then package from it.
+      # libmpv travels with us, so nothing depends on a host one - which also
+      # removes the transitive pull of everything libmpv links, hence bundle-libs
+      # before packaging rather than after.
+      - name: Copy libmpv into the bundle
+        run: |
+          BUNDLE_LIB=build/linux/x64/release/bundle/lib
+          LIBMPV_DIR=$(dirname "$(find libmpv-prefix -name 'libmpv.so' | head -1)")
+          cp -a "$LIBMPV_DIR"/libmpv.so* "$BUNDLE_LIB/"
+          cp -a libmpv-prefix/lib/libshaderc_shared.so* "$BUNDLE_LIB/"
+
+      - name: Bundle shared libraries
+        run: bash linux/packaging/bundle-libs.sh build/linux/x64/release/bundle
+
+      - name: Copy wrapper script into the bundle
+        run: cp linux/packaging/plezy.sh build/linux/x64/release/bundle/plezy.sh
+
+      # Derives what the resolved bundle still needs from the host and proves
+      # every one of those libraries is declared. This is the check that would
+      # have caught bundling libmpv without also declaring what libmpv links.
+      - name: Verify every unbundled library the bundle needs is declared
+        run: python3 linux/packaging/check-bundle-host-deps.py build/linux/x64/release/bundle
+
+      # OUTPUT_DIR defaults to the repo root; name it so the paths below are not
+      # a guess about where fpm dropped things. The host-dependency guard is
+      # skipped because the named step above just ran it against this same
+      # bundle; the internal run exists for by-hand packaging outside CI.
+      - name: Build the packages
+        run: |
+          mkdir -p "$OUTPUT_DIR"
+          python3 linux/packaging/build-packages.py
+        env:
+          OUTPUT_DIR: ${{ github.workspace }}/packages
+          PLEZY_SKIP_HOST_DEP_CHECK: "1"
+
+      # The guard above reconciles the depends lists with the staged bundle; only
+      # the packages themselves can show that list survived fpm. Every name comes
+      # from build-packages.py, so adding a library there is verified here without
+      # a second edit - and this job is off by default, so a hand-copied list
+      # would rot unseen. The release job in build.yml runs the same script
+      # against the artifacts users install, so the assertions cannot drift.
+      - name: Verify the declared dependencies reached the package metadata
+        run: python3 linux/packaging/check-package-deps.py "${{ github.workspace }}/packages"
+
+      # Same resolved bundle the packages were cut from, so the tarball is not a
+      # second, differently-assembled artifact. It is the one to put on a USB for
+      # a foreign machine, because it needs nothing installed.
+      - name: Create the tarball
+        run: |
+          BUNDLE_DIR=build/linux/x64/release/bundle
+          mkdir -p "$OUTPUT_DIR"
+          tar -czf "$OUTPUT_DIR/plezy-linux-x64.tar.gz" -C "$BUNDLE_DIR" .
+          echo "=== libmpv travelling in every artifact ==="
+          ldd "$BUNDLE_DIR/lib/libmpv.so" | grep -iE 'wayland|libX11|vdpau' || echo '(none)'
+        env:
+          OUTPUT_DIR: ${{ github.workspace }}/packages
+
+      - name: Upload the packages
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
+        with:
+          name: linux-packages-smoke
+          path: ${{ github.workspace }}/packages/plezy-linux-x64.*
+          if-no-files-found: error
+          retention-days: 7