feat: Implement Remotion video rendering API with TTS, word timings, and Docker pre-bundling.

scripts/prebundle-remotion.js

@@ -0,0 +1,9 @@
+#!/usr/bin/env node
+// Pre-bundle Remotion composition during Docker build.
+// This warms up the Webpack cache so the first user render is fast.
+const { bundle } = require('@remotion/bundler');
+const path = require('path');
+
+bundle({ entryPoint: path.resolve(__dirname, '../client/src/remotion/index.ts') })
+  .then(loc => console.log('✅ Remotion pre-bundle OK:', loc))
+  .catch(e  => { console.warn('⚠️ Remotion pre-bundle skipped:', e.message); process.exit(0); });