Replace FixMap workflow video

[aryamthecodebreaker]

Summary

• replace the optional homepage workflow video with the user-provided 31-second cut
• replace its poster with the matching poster frame
• give the soundtrack a creative-direction pass using the prior FixMap instrumental bed plus restrained frame-synchronized UI cues
• preserve the supplied H.264 visual stream byte-for-byte

Validation

• npm run lint -w @fixmap/web
• npm run typecheck -w @fixmap/web
• npm run build:web
• local browser smoke at http://localhost:3200: meaningful page content, no framework error overlay, video readyState 4, 1920x1080, 31 seconds, playback completed
• source/output H.264 elementary-stream SHA-256: 55b0b86f8e1d1a6537e46cdf19d0f40c659a43b06be23d243deaeb2e5d6e5fcc
• final MP4 SHA-256: b599c977e99474d54be485408cb8a4129a3559f110114b52215fa3d9d38307b0

No website code or copy changed. No paid API or controlled-agent runs were executed.