feat: add Remotion video project + SquareMCP brand compositions

- Scaffold videos/remotion-demo with Remotion 4.0.459
- SquareMCPLinkedIn: 90s 1080×1080 LinkedIn explainer (6 scenes, spring animations)
- SquareMCPHeroLoop: 30s 1920×1080 seamless hero loop (node network + MCP layer + logo)
- Brand tokens from squaremcp-logo.svg (#0E63F6/#7DB6FF), Inter via @remotion/google-fonts
- Both compositions rendered to out/ and type-checked clean
- Update .gitignore to exclude videos/remotion-demo/node_modules and out/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

videos/remotion-demo/eslint.config.mjs

@@ -0,0 +1,3 @@
+import { config } from "@remotion/eslint-config-flat";
+
+export default config;