CI: install ffmpeg and imagemagick before running tests

The test suite is integration tests that shell out to ffmpeg/ffprobe
and ImageMagick's `convert`. Without those binaries the tests fail with
"FFmpeg is not installed or not available in PATH". Add an apt install
step to both the CI and test workflows so the runner has them.

Verified locally: 85 passing, 12 pending, 0 failing.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ralyodio

.github/workflows/ci.yml

@@ -23,6 +23,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      # The test suite shells out to ffmpeg/ffprobe and ImageMagick's convert;
+      # install them so the integration tests can run on the runner.
+      - name: Install FFmpeg and ImageMagick
+        run: sudo apt-get update && sudo apt-get install -y ffmpeg imagemagick
+
       # pnpm version is read from the "packageManager" field in package.json.
       # Do not pin a version here — it conflicts with packageManager and fails
       # with ERR_PNPM_BAD_PM_VERSION.

.github/workflows/test.yml

@@ -19,6 +19,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      # The test suite shells out to ffmpeg/ffprobe and ImageMagick's convert;
+      # install them so the integration tests can run on the runner.
+      - name: Install FFmpeg and ImageMagick
+        run: sudo apt-get update && sudo apt-get install -y ffmpeg imagemagick
+
       # pnpm version is read from the "packageManager" field in package.json.
       # Do not pin a version here — it conflicts with packageManager and fails
       # with ERR_PNPM_BAD_PM_VERSION.