feat(skills): improve hyperframes composition quality rules (#250)

## Summary

Overhaul the hyperframes composition skill based on 26 eval rounds (~100 generated compositions). The goal: prevent known AI design tells and composition bugs while giving the LLM maximum creative freedom.

### Typography (`fonts.md` → `typography.md`)
- Two-tier banned font list (32 fonts): tier 1 bans training-data defaults, tier 2 bans the reflex replacements
- Font discovery script: queries Google Fonts API, 5 dynamic categories, top 5 randomized per run
- Selection philosophy: register-first thinking, cross-check assumptions

### Google Fonts on-demand (`deterministicFonts.ts`)
- Any Google Font works without pre-bundling — compiler fetches woff2 at compile time
- Cached to `~/.cache/hyperframes/fonts/<slug>/<weight>-<style>.woff2`
- Parallel woff2 fetches via `Promise.allSettled` (was sequential)
- Single `mkdirSync({ recursive: true })` per family (was `existsSync` x11)
- Skip redundant `readFileSync` when buffer is already in memory from fetch

### Layout rules (`SKILL.md`)
- Flexbox with gap for content text — prevents overlap from absolute positioning
- `position: absolute` reserved for decoratives only
- Cards/containers explicitly banned

### Background layer (`house-style.md`)
- 3-5 persistent decorative elements per scene (glows, ghost text, accent lines)
- All decoratives MUST have ambient GSAP animation — static decoratives banned
- WRONG/RIGHT code examples

### Transition rules (`SKILL.md`)
- Always use transitions, always entrance animations, exit animations banned except final scene
- WRONG/RIGHT code examples showing banned exit patterns

### Other
- Flash cut transition removed
- CLAUDE.md: `bun install` / `bun run build` / `bun run test` (was pnpm)
- house-style.md trimmed from 184 to ~80 lines
- SKILL.md trimmed from 364 to ~230 lines

## Test plan
- [ ] `bun install` succeeds, workspace links resolve
- [ ] `bun run build` succeeds
- [ ] `npx hyperframes lint` passes on existing compositions
- [ ] Generate a composition with `/hyperframes` skill — verify flexbox, background decoratives with animation, entrance-only animations, no banned fonts
- [ ] Verify Google Fonts on-demand: use a non-bundled font, run `npx hyperframes preview`

🤖 Generated with [Claude Code](https://claude.com/claude-code)

skills/hyperframes/references/transitions/css-other.md

@@ -1,16 +1,5 @@
 ## Other
 
-### Flash Cut
-
-White full-screen overlay flashes at swap point. 0.03s on, 0.1s off.
-
-```js
-tl.to("#flash-overlay", { opacity: 1, duration: 0.03, ease: "power4.out" }, T);
-tl.set(old, { opacity: 0 }, T + 0.03);
-tl.set(new, { opacity: 1 }, T + 0.03);
-tl.to("#flash-overlay", { opacity: 0, duration: 0.1, ease: "power2.out" }, T + 0.05);
-```
-
 ### Gravity Drop
 
 Old scene falls down with slight rotation. New scene was behind it. Needs z-index.