feat: social video uploads + hero page video + TikTok content

Hero page:
- Replace GIF with squaremcp-hero-loop.mp4 (autoplay, muted, loop)
- Update styles, scripts, tests, Dockerfile, baselines
- Deployed and verified

Social video uploads:
- Twitter/X: uploadVideoAndTweet via v1.1 media/upload + v2 tweets
- Facebook: createVideoPost via Graph API /{pageId}/videos
- Instagram: createReel via Graph API (container → poll → publish)
- TikTok: REST endpoints + OpenAPI schema for video upload

Marketing:
- TikTok content prompts, scripts, and posting schedule

Note: Remotion not mentioned in any user-facing content

product/site/styles.css

@@ -271,7 +271,8 @@ h3 {
   background: #08111f;
 }
 
-.hero-media img {
+.hero-media img,
+.hero-media video {
   display: block;
   width: 100%;
   height: auto;