refactor(lint): break 1,314-line monolith into focused rule modules with plugin system

[miguel-heygen]

Summary

• Breaks hyperframeLinter.ts from 1,314 lines (one massive function) into a plugin system of focused rule modules
• Introduces LintContext — HTML is parsed once and shared across all rules
• Adds LintRule<TContext> type as the formal contract for rules
• Public API unchanged: lintHyperframeHtml, lintMediaUrls, lintScriptUrls signatures identical

New file structure

src/lint/
  utils.ts          — shared types (OpenTag, ExtractedBlock), regex constants, helpers
  context.ts        — LintContext type + buildLintContext() factory
  rules/
    core.ts         — structural rules (root attrs, timeline registry, script syntax)
    media.ts        — media element rules (duplicate ids, video pitfalls, placeholder URLs, etc.)
    gsap.ts         — GSAP rules + GSAP-specific parsing utils
    captions.ts     — caption rules
    composition.ts  — timed element, deprecated attrs, template literal selector, external scripts
    adapters.ts     — Lottie + Three.js missing-script rules (from PR #149)
  hyperframeLinter.ts — orchestrator only (~200 lines, down from 1,314)

Adding a new adapter rule going forward

1. Create src/lint/rules/my-adapter.ts exporting myAdapterRules: LintRule[]
2. Import and spread into ALL_RULES in hyperframeLinter.ts

Test plan

• All 402 core tests pass unchanged
• Full workspace build clean (pnpm build)
• TypeScript strict mode clean (pnpm tsc --noEmit)

[miguel-heygen]

Merge activity

• Mar 31, 10:50 PM UTC: @miguel-heygen merged this pull request with Graphite.