build: add macOS universal libmpv.dylib CI build

Vendor ci/build-libmpv-macos.sh, which builds every dependency statically
for the native runner architecture and links them into a single
self-contained libmpv dylib (coreaudio output, videotoolbox hardware
decode, OpenGL render API; no vulkan/cocoa player). build-macos.yml runs
it on macos-14 (x86_64) and macos-15 (arm64) in parallel and a merge job
combines the two dylibs into one universal libmpv.dylib with lipo, matching
the file name jlibmpv expects on macOS.

.github/workflows/build-macos-arch.yml

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+name: build-macos-arch
+
+# Builds the self-contained libmpv dylib for one macOS architecture
+# (x86_64 on macos-14, arm64 on macos-15) using the vendored build script.
+# The merge job in build-macos.yml combines the per-architecture dylibs into
+# a universal binary.
+
+on:
+  workflow_call:
+    inputs:
+      arch:
+        description: Target architecture (x86_64 or arm64)
+        required: true
+        type: string
+      runner:
+        description: GitHub runner image providing that architecture
+        required: true
+        type: string
+
+env:
+  MPV_REF: v0.41.0
+  ARCH: ${{ inputs.arch }}
+
+jobs:
+  build:
+    runs-on: ${{ inputs.runner }}
+    env:
+      CCACHE_BASEDIR: ${{ github.workspace }}
+      CCACHE_DIR: ${{ github.workspace }}/.ccache
+      CCACHE_MAXSIZE: 500M
+    steps:
+      - name: Check out mpv-natives (build scripts)
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Check out mpv (pinned tag)
+        uses: actions/checkout@v4
+        with:
+          repository: mpv-player/mpv
+          ref: ${{ env.MPV_REF }}
+          path: mpv
+          fetch-depth: 1
+
+      - name: Get time
+        id: get_time
+        run: echo "timestamp=$(date +%s)" >> $GITHUB_OUTPUT
+
+      - name: Restore ccache
+        uses: actions/cache/restore@v4
+        with:
+          path: ${{ env.CCACHE_DIR }}
+          key: macos-${{ env.ARCH }}-${{ steps.get_time.outputs.timestamp }}
+          restore-keys: macos-${{ env.ARCH }}-
+
+      - name: Install dependencies
+        run: |
+          brew install ccache nasm ninja
+          python3 -m pip install --user meson
+          export PATH="$HOME/Library/Python/3.12/bin:$PATH"
+          # export so meson finds pip-installed tools
+          echo "$HOME/Library/Python/3.12/bin" >> "$GITHUB_PATH"
+
+      # Run the vendored build script from inside the mpv source tree, so the
+      # native build writes macos_prefix/ and the meson build next to mpv's
+      # meson.build and produces the self-contained dylib in mpv/artifact/.
+      - name: Build self-contained libmpv
+        working-directory: mpv
+        run: bash "${{ github.workspace }}/ci/build-libmpv-macos.sh"
+
+      - name: Print meson log on failure
+        if: failure()
+        run: cat mpv/macos_build/meson-logs/meson-log.txt
+
+      - name: Collect artifact
+        run: |
+          mkdir -p "artifact-macos-${{ env.ARCH }}"
+          cp -pv mpv/artifact/libmpv-2.dylib "artifact-macos-${{ env.ARCH }}/"
+          cp -pv mpv/artifact/*.h "artifact-macos-${{ env.ARCH }}/" 2>/dev/null || true
+          echo "=== contents ==="
+          ls -l "artifact-macos-${{ env.ARCH }}"
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: mpv-natives-macos-${{ env.ARCH }}-mpv-${{ env.MPV_REF }}
+          path: artifact-macos-${{ env.ARCH }}
+
+      - name: Save ccache
+        uses: actions/cache/save@v4
+        if: always()
+        with:
+          path: ${{ env.CCACHE_DIR }}
+          key: macos-${{ env.ARCH }}-${{ steps.get_time.outputs.timestamp }}

.github/workflows/build-macos.yml

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+name: build-macos
+
+# Builds a universal (arm64 + x86_64) self-contained libmpv.dylib for macOS
+# from mpv source pinned to a release tag. Two native builds run in parallel
+# (x86_64 on macos-14, arm64 on macos-15); a merge job combines the two dylibs
+# with lipo into one universal library and uploads it.
+#
+# Every dependency is built static and linked into the one dylib (same
+# approach as the Windows build). jlibmpv expects the file name
+# `libmpv.dylib` (no -2) and one universal binary for both architectures.
+#
+# Pinned to mpv v0.41.0 — the version whose client API (131077) the jlibmpv
+# JNA bindings are validated against. Bump the ref here for a libmpv update.
+# The build recipe lives in ci/build-libmpv-macos.sh in this repository.
+
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+env:
+  MPV_REF: v0.41.0
+
+jobs:
+  build-x86_64:
+    uses: ./.github/workflows/build-macos-arch.yml
+    with:
+      arch: x86_64
+      runner: macos-14
+
+  build-arm64:
+    uses: ./.github/workflows/build-macos-arch.yml
+    with:
+      arch: arm64
+      runner: macos-15
+
+  merge:
+    needs: [build-x86_64, build-arm64]
+    runs-on: macos-15
+    steps:
+      - name: Check out mpv-natives (build scripts)
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Check out mpv (pinned tag)
+        uses: actions/checkout@v4
+        with:
+          repository: mpv-player/mpv
+          ref: ${{ env.MPV_REF }}
+          path: mpv
+          fetch-depth: 1
+
+      - name: Download architecture artifacts
+        uses: actions/download-artifact@v4
+        with:
+          pattern: mpv-natives-macos-${{ env.MPV_REF }}-*
+          path: arch
+          merge-multiple: true
+
+      - name: Create universal dylib
+        run: |
+          mkdir -p artifact-libmpv
+          lipo -create \
+            "arch/x86_64/libmpv-2.dylib" \
+            "arch/arm64/libmpv-2.dylib" \
+            -output artifact-libmpv/libmpv.dylib
+          lipo -info artifact-libmpv/libmpv.dylib
+          cp -pv mpv/mpvrender.h mpv/mpv/client.h mpv/ebml_types.h artifact-libmpv/ 2>/dev/null || true
+          sha256sum artifact-libmpv/libmpv.dylib > artifact-libmpv/checksums.txt
+          cat artifact-libmpv/checksums.txt
+          ls -l artifact-libmpv
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: mpv-natives-macos-universal-mpv-${{ env.MPV_REF }}
+          path: artifact-libmpv