fix(player): an embed without a height shows its film, and heavy films are measured in Safari (#5932)

* test(player): measure heavy films in real Safari and Chrome on macOS

* test(player): count runtime media seeks and rate writes during the Safari bench

* test(player): compare the Safari bench against native playback of the same media

* test(player): split Safari control playback into per-frame media writes and per-frame transforms

* perf(core): write media volume and mute only when they change

* test(player): presented frame rate and compositor-animation controls in the Safari bench

* perf(core): keep the media volume guard without a new comment line

* test(player): derive presented frames from playback counters and snapshot video state

* test(player): control page plays only listed media, and anchor the Safari process match

* test(player): send the bench as code, and write only validated numbers from the browser

* fix(player): perf host page gives the player a real box, so films are on screen when measured

* fix(player): a player with no height set takes its film's shape instead of collapsing to nothing

The player box had no intrinsic height, so an embed that set only a width (or nothing) was 0 px tall
and showed no picture. An in-flow sizer now carries the composition's aspect ratio; a height the
embed sets still wins, and a height-only embed keeps its full width.

* test(player): label each embed on the player box page

.github/workflows/player-perf.yml

@@ -140,6 +140,13 @@ jobs:
           PUPPETEER_EXECUTABLE_PATH: ${{ steps.setup-chrome.outputs.chrome-path }}
         run: bun run test:browser-raster
 
+      - name: Verify the player takes the box its embed asks for (load shard only)
+        if: matrix.shard == 'load'
+        working-directory: packages/player
+        env:
+          PUPPETEER_EXECUTABLE_PATH: ${{ steps.setup-chrome.outputs.chrome-path }}
+        run: bun run test:browser-box
+
       - name: Run player perf — ${{ matrix.shard }} (measure mode)
         working-directory: packages/player
         env:

.github/workflows/player-safari.yml

@@ -0,0 +1,63 @@
+name: Player Safari perf
+
+permissions:
+  contents: read
+
+env:
+  HYPERFRAMES_NO_TELEMETRY: "1"
+
+on:
+  pull_request:
+    paths:
+      - "packages/player/**"
+      - "packages/core/src/runtime/**"
+      - ".github/workflows/player-safari.yml"
+  schedule:
+    - cron: "23 7 * * *"
+  workflow_dispatch:
+
+concurrency:
+  group: player-safari-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  heavy-films:
+    name: "Heavy films: Safari vs Chrome"
+    runs-on: macos-latest
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+
+      - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
+
+      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: 22
+
+      - run: bun install --frozen-lockfile
+
+      # The bench serves packages/player/dist and packages/core/dist, as the Linux perf shards do.
+      - run: bun run build
+
+      - name: Generate heavy media
+        run: |
+          brew install ffmpeg
+          bash packages/player/tests/perf/browsers/make-media.sh
+
+      - name: Enable safaridriver
+        run: sudo safaridriver --enable
+
+      - name: Run heavy films in Safari and Chrome
+        working-directory: packages/player
+        run: |
+          sw_vers
+          CHROMEDRIVER="$CHROMEWEBDRIVER/chromedriver" bun run tests/perf/browsers/run.ts --browsers safari,chrome --runs 2
+
+      - name: Upload results
+        if: always()
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+        with:
+          name: player-safari-heavy-films
+          path: packages/player/tests/perf/results/
+          if-no-files-found: warn
+          retention-days: 30