feat: sync animated anki images to sentence audio

src/media-generator.test.ts

@@ -0,0 +1,15 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+
+import { buildAnimatedImageVideoFilter } from './media-generator';
+
+test('buildAnimatedImageVideoFilter prepends a cloned first frame when lead-in is provided', () => {
+  assert.equal(
+    buildAnimatedImageVideoFilter({
+      fps: 10,
+      maxWidth: 640,
+      leadingStillDuration: 1.25,
+    }),
+    'tpad=start_duration=1.25:start_mode=clone,fps=10,scale=w=640:h=-2',
+  );
+});