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

.fallowrc.jsonc

@@ -0,0 +1,92 @@
+{
+  "$schema": "https://raw.githubusercontent.com/fallow-rs/fallow/main/config-schema.json",
+  "entry": [
+    "packages/producer/src/**/*.test.ts",
+    "packages/aws-lambda/src/**/*.test.ts",
+    "packages/producer/src/regression-harness.ts",
+    "packages/producer/src/regression-harness-distributed.test.ts",
+    "packages/producer/src/regression-harness-lambda-local.ts",
+    "packages/producer/src/transparency-test.ts",
+    "packages/producer/src/parity-harness.ts",
+    "packages/producer/src/parity-fixtures.ts",
+    "packages/producer/src/perf-gate.ts",
+    "packages/producer/src/runtime-conformance.ts",
+    "packages/producer/src/benchmark.ts",
+    "packages/producer/scripts/generate-font-data.ts",
+    "packages/cli/scripts/generate-font-data.ts",
+    "packages/engine/scripts/test-fitTextFontSize-browser.ts",
+    "packages/aws-lambda/scripts/*.ts",
+    // Built as standalone IIFE for the browser-side sandbox runtime;
+    // referenced by file path (not import) in build-hyperframes-runtime-artifact.ts.
+    "packages/core/src/runtime/entry.ts",
+    // Worker entry points loaded dynamically by their *Pool.ts companions.
+    "packages/producer/src/services/pngDecodeBlitWorker.ts",
+    "packages/producer/src/services/shaderTransitionWorker.ts",
+    "scripts/*.{ts,mjs,js}",
+    "scripts/*/run.mjs"
+  ],
+  "ignorePatterns": [
+    "docs/**",
+    "packages/producer/tests/**",
+    "packages/player/tests/**",
+    "packages/engine/tests/**",
+    "skills/**/test-corpus/**",
+    "skills/**/scripts/**",
+    "registry/**",
+    "examples/**",
+    ".github/workflows/fixtures/**"
+  ],
+  "ignoreExports": [
+    // CLI command files: every command exports a const `examples` per the
+    // convention documented in CLAUDE.md. This is a namespace barrel, not a
+    // collision.
+    { "file": "packages/cli/src/commands/*.ts", "exports": ["examples"] },
+    // Independent ML model managers each declare their own DEFAULT_MODEL /
+    // MODELS_DIR / ensureModel for their model namespace.
+    {
+      "file": "packages/cli/src/{background-removal,tts,whisper}/manager.ts",
+      "exports": ["DEFAULT_MODEL", "MODELS_DIR", "ensureModel"]
+    },
+    // `isPathInside` is documented as exported-for-tests only in fileServer.ts;
+    // it has different semantics (symlink resolution) from utils/paths.ts.
+    {
+      "file": "packages/producer/src/services/fileServer.ts",
+      "exports": ["isPathInside"]
+    }
+  ],
+  "ignoreDependencies": [
+    // Runtime/dynamic deps not visible to static analysis: tsup `external`,
+    // dynamic require() resolution, peer/static-file consumption in tests,
+    // and bun-hoisted workspace devDeps (e.g. happy-dom in root package.json
+    // resolves for every workspace, so workspaces don't redeclare it).
+    "puppeteer",
+    "puppeteer-core",
+    "esbuild",
+    "giget",
+    "gsap",
+    "happy-dom",
+    "ffmpeg-static",
+    "ffprobe-static",
+    "@hyperframes/core",
+    "@hyperframes/studio",
+    "@hyperframes/producer",
+    "@fontsource/archivo-black",
+    "@fontsource/eb-garamond",
+    "@fontsource/ibm-plex-mono",
+    "@fontsource/inter",
+    "@fontsource/jetbrains-mono",
+    "@fontsource/league-gothic",
+    "@fontsource/montserrat",
+    "@fontsource/nunito",
+    "@fontsource/oswald",
+    "@fontsource/outfit",
+    "@fontsource/space-mono",
+    "@fontsource/lato",
+    "@fontsource/noto-sans-jp",
+    "@fontsource/open-sans",
+    "@fontsource/playfair-display",
+    "@fontsource/poppins",
+    "@fontsource/roboto",
+    "@fontsource/source-code-pro"
+  ]
+}