chore: add fallow config and fix high-signal findings

Configure fallow via .fallowrc.jsonc so its analysis reflects this repo's
real entry surface, then fix the genuine issues it found.

Fallow noise reduction (601 → 276 dead-code findings):
- Ignore docs/, test fixtures, skill test-corpora, registry/, examples/
- Declare worker entry points loaded dynamically by file path
  (pngDecodeBlitWorker.ts, shaderTransitionWorker.ts)
- Declare runtime IIFE entry (core/src/runtime/entry.ts) built outside the
  import graph by build-hyperframes-runtime-artifact.ts
- Declare bun:test files in producer + aws-lambda as test entries
- Ignore dynamically-resolved deps: tsup external (puppeteer-core, esbuild,
  giget), peer/static-file (gsap in player perf tests), workspace deps
  hoisted by bun (happy-dom, @hyperframes/*), and @fontsource/* packages
  read via readFileSync in generate-font-data.ts

Extract inline build:fonts scripts:
- packages/{cli,producer}/package.json had multi-line `node -e ...` blobs
  containing braces that fallow mis-parsed as glob alternate groups. Moved
  to dedicated build-fonts.mjs scripts.

Fix duplicate exports:
- Remove dead FileIcon alias in studio/SystemIcons.tsx (FileTreeIcons.tsx
  has the real, used one)
- Consolidate ValidationResult: drop the identical duplicate in
  gsapParser.ts; both parsers now import from core.types
- Suppress intentional namespace patterns (per-namespace ML manager
  exports; CLI per-command 'examples' convention; fileServer.ts test-only
  isPathInside which has different symlink semantics from utils/paths.ts)

Break circular dep (studio/components/editor):
- manualEditsDom.ts re-exported clearStudioPathOffset / clearStudioRotation
  / clearStudioBoxSize from manualEditsSnapshot.ts, which imports four
  helpers from manualEditsDom.ts — back-edge cycle
- Re-export moved to manualEdits.ts (the package-public barrel) where the
  rest of the snapshot re-exports already live; underlying files now form
  a clean DAG

Remove genuinely unused deps:
- studio: motion (no imports anywhere), codemirror (umbrella package; the
  @codemirror/* sub-packages are used directly)
- cli: mime-types (plus its only consumer src/utils/mime.ts, which was a
  hardcoded mime table that didn't use the package), and its now-stale
  tsup external entry

Verified: typecheck across core/cli/producer/studio is clean, oxlint
+ oxfmt pass, manualEdits.test.ts (18 tests) and core parser tests (69
tests) still pass.

Deferred follow-ups (real findings, separate PRs):
- 8 circular deps in producer/services/render/stages/ — renderOrchestrator
  ↔ captureHdr* / captureStage / extractVideosStage form a hub cycle
- ~14 unused files in producer/src/services/ that look like dead
  re-export shims to @hyperframes/engine, but aren't in the public
  exports map — need to confirm no deep-import consumers before deletion
- waveform.ts complexity hotspot

packages/cli/package.json

@@ -18,7 +18,7 @@
     "test": "vitest run",
     "dev": "tsx src/cli.ts",
     "build": "bun run build:fonts && tsup && bun run build:runtime && bun run build:copy",
-    "build:fonts": "node -e \"const fs=require('fs');if(!fs.existsSync('../producer/src/services/fontData.generated.ts')){const {execSync}=require('child_process');execSync('cd ../producer && tsx scripts/generate-font-data.ts',{stdio:'inherit'})}else{console.log('[build:fonts] skipped — fontData.generated.ts already exists')}\"",
+    "build:fonts": "node scripts/build-fonts.mjs",
     "build:runtime": "tsx scripts/build-runtime.ts",
     "build:copy": "node scripts/build-copy.mjs",
     "typecheck": "tsc --noEmit"
@@ -32,7 +32,6 @@
     "esbuild": "^0.25.12",
     "giget": "^3.2.0",
     "hono": "^4.0.0",
-    "mime-types": "^3.0.2",
     "onnxruntime-node": "^1.20.0",
     "open": "^10.0.0",
     "postcss": "^8.5.8",