Homepage demo: cinematic split-pane 100x rebuild

- public/demo-90s.html: rebuilt as terminal+visual pane with chapter
  progress bar, animated K-Score gauge, slide-in receipt card,
  animated savings ticker ($4,125.80 counter), 3 cascading metric
  tiles. Cool slate palette throughout (no warm tones). Real model
  names: claude-sonnet-4-6, gpt-4o, deepseek-v3, qwen2.5-7b-instruct.
- public/demo-90s.mp4 + poster: re-recorded against new HTML via
  Playwright + ffmpeg (1280x720, libx264 crf 23, faststart).
- public/index.html: video embed now wrapped in gradient-border shell
  (cyan->slate->green via mask trick), floating Replay button
  (top-right, opacity-on-hover, backdrop-blur), 4-chapter strip below
  frame (00 Intro / 01 Route & Capture / 02 Distill & Compile /
  03 Run & Verify) with responsive 760/640px collapse.
- public/sw.js: CACHE_VERSION 132 -> 133,
  slug kolm-v133-2026-05-28-demo-90s-cinematic-split-pane.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: sneaky-hippo