## Summary

Adds critical rendering constraints to the `hyperframes` skill discovered from eval analysis of 27 agent-generated compositions. These guardrails prevent agents from producing compositions that technically work but render poorly.

## What it fixes

| Rule Added | Eval Prompts Affected | Issue |
| --- | --- | --- |
| Ban `repeat: -1` | #20 loading-spinner (2.0/5) | Infinite timeline broke capture engine |
| Ban async timeline construction | #16 particle-logo (2.6/5) | Timeline empty at capture time |
| Min font size 16px (labels), 20px (body) | #7, #8, #13, #14, #15, #19 | Illegible text after encoding |
| Ban full-screen dark linear gradients | #3, #5, #10, #14 | H.264 color banding |
| `<link>` fonts over CSS `@import` | #7, #24 | Font loading race conditions |

## Changes

- **Rules section**: Added `repeat: -1` ban, async timeline ban, items 8-9 to "Never do" list
- **Typography section**: Expanded font size guidance with specific minimums per text role (headlines, body, labels)
- **New "Backgrounds and Color" section**: Guidance on avoiding gradient banding
- **Output Checklist**: 5 new items covering all new constraints

## Test plan

- [ ] Run eval with updated skill and compare avg quality scores
- [x] Skill renders correctly in `/hyperframes` invocation

Blockers:
- #2: late_init_set false positive on fractional opacity (0.5 matched as 0)
  Fixed: /opacity\s*:\s*0(?![.\d])/ negative lookahead
- #3: scene-1 prefix skip matches scene 10+ (s1- matches s10-)
  Fixed: extract full number and compare exactly

High severity:
- #4: autoAlpha not covered by late_init_set
  Fixed: checks both opacity and autoAlpha
- #5: al() crashes on non-hex colors (#fff shorthand, rgb(), null)
  Fixed: guard + shorthand expansion + NaN fallback
- #6: "Full palette" with null bg crashes isDark
  Fixed: null guard defaults to dark
- #7: template literals missed by tl_from_in_multiscene
  Fixed: regex includes backtick quotes

Medium:
- #9: no retry limit on eval failures → infinite loop
  Fixed: max 2 retries, then escalate to user
- #10: vague ID convention
  Fixed: explicit s{N}- prefix rule in multi-scene.md
- #11: visual-style.md backward compat
  Fixed: Step 0b checks both filenames
- #13: preview_html script injection
  Fixed: documented prohibition in design-picker.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Three concrete bugs found while auditing PR #991:

1. html-in-canvas-patterns.md (#1 in catalog, 3D Rotation with Bloom):
   The code example used `new THREE.EffectComposer(renderer)` UMD-style
   namespace access while the ESM imports right below pull them in as
   bare named imports. Three.js r150+ removed the UMD `examples/js/`
   globals, so as written the example throws `TypeError:
   THREE.EffectComposer is not a constructor`. Switched to the bare
   names matching the imports. THREE.Vector2 stays as-is — Vector2 is
   on the THREE namespace.

2. techniques.md (#5, Lottie Animation): The CDN path
   `@lottiefiles/dotlottie-web/dist/dotlottie-player.js` returns 404.
   `@lottiefiles/dotlottie-web` is the JavaScript SDK, not a web
   component — its `main` is `dist/index.cjs`. The web-component
   package is `@lottiefiles/dotlottie-wc` and the custom element is
   `<dotlottie-wc>`, not `<dotlottie-player>`. Updated both.

3. techniques.md (5 occurrences across Lottie / lottie-web /
   Video / @font-face examples): asset paths used the `../capture/`
   pattern that PR #989's `invalid_capture_path` lint rule emits an
   error for. Replaced all with root-relative `capture/...`. PRs #989
   and #991 are no longer self-contradictory.

Three concrete bugs found while auditing PR #991:

1. html-in-canvas-patterns.md (#1 in catalog, 3D Rotation with Bloom):
   The code example used `new THREE.EffectComposer(renderer)` UMD-style
   namespace access while the ESM imports right below pull them in as
   bare named imports. Three.js r150+ removed the UMD `examples/js/`
   globals, so as written the example throws `TypeError:
   THREE.EffectComposer is not a constructor`. Switched to the bare
   names matching the imports. THREE.Vector2 stays as-is — Vector2 is
   on the THREE namespace.

2. techniques.md (#5, Lottie Animation): The CDN path
   `@lottiefiles/dotlottie-web/dist/dotlottie-player.js` returns 404.
   `@lottiefiles/dotlottie-web` is the JavaScript SDK, not a web
   component — its `main` is `dist/index.cjs`. The web-component
   package is `@lottiefiles/dotlottie-wc` and the custom element is
   `<dotlottie-wc>`, not `<dotlottie-player>`. Updated both.

3. techniques.md (5 occurrences across Lottie / lottie-web /
   Video / @font-face examples): asset paths used the `../capture/`
   pattern that PR #989's `invalid_capture_path` lint rule emits an
   error for. Replaced all with root-relative `capture/...`. PRs #989
   and #991 are no longer self-contradictory.

Three concrete bugs found while auditing PR #991:

1. html-in-canvas-patterns.md (#1 in catalog, 3D Rotation with Bloom):
   The code example used `new THREE.EffectComposer(renderer)` UMD-style
   namespace access while the ESM imports right below pull them in as
   bare named imports. Three.js r150+ removed the UMD `examples/js/`
   globals, so as written the example throws `TypeError:
   THREE.EffectComposer is not a constructor`. Switched to the bare
   names matching the imports. THREE.Vector2 stays as-is — Vector2 is
   on the THREE namespace.

2. techniques.md (#5, Lottie Animation): The CDN path
   `@lottiefiles/dotlottie-web/dist/dotlottie-player.js` returns 404.
   `@lottiefiles/dotlottie-web` is the JavaScript SDK, not a web
   component — its `main` is `dist/index.cjs`. The web-component
   package is `@lottiefiles/dotlottie-wc` and the custom element is
   `<dotlottie-wc>`, not `<dotlottie-player>`. Updated both.

3. techniques.md (5 occurrences across Lottie / lottie-web /
   Video / @font-face examples): asset paths used the `../capture/`
   pattern that PR #989's `invalid_capture_path` lint rule emits an
   error for. Replaced all with root-relative `capture/...`. PRs #989
   and #991 are no longer self-contradictory.

Three concrete bugs found while auditing PR #991:

1. html-in-canvas-patterns.md (#1 in catalog, 3D Rotation with Bloom):
   The code example used `new THREE.EffectComposer(renderer)` UMD-style
   namespace access while the ESM imports right below pull them in as
   bare named imports. Three.js r150+ removed the UMD `examples/js/`
   globals, so as written the example throws `TypeError:
   THREE.EffectComposer is not a constructor`. Switched to the bare
   names matching the imports. THREE.Vector2 stays as-is — Vector2 is
   on the THREE namespace.

2. techniques.md (#5, Lottie Animation): The CDN path
   `@lottiefiles/dotlottie-web/dist/dotlottie-player.js` returns 404.
   `@lottiefiles/dotlottie-web` is the JavaScript SDK, not a web
   component — its `main` is `dist/index.cjs`. The web-component
   package is `@lottiefiles/dotlottie-wc` and the custom element is
   `<dotlottie-wc>`, not `<dotlottie-player>`. Updated both.

3. techniques.md (5 occurrences across Lottie / lottie-web /
   Video / @font-face examples): asset paths used the `../capture/`
   pattern that PR #989's `invalid_capture_path` lint rule emits an
   error for. Replaced all with root-relative `capture/...`. PRs #989
   and #991 are no longer self-contradictory.

- dedup safeLocalStorage/safeSessionStorage into utils/safeStorage.ts,
  used by both telemetry/config.ts and telemetry/distinctId.ts (Miga #6)
- replace redundant `??=` with `=` in the no-storage branch; cachedId is
  guaranteed null there (Miga #2)
- extract buildStudioHeadScripts() so the "identity script before env
  script" head-injection ordering is a pure, tested invariant (Miga #5)
- add tests: head-script ordering + telemetry-off passthrough, and a
  Studio memoization test proving an adopted CLI id survives a later
  window.__HF_CLI_DISTINCT_ID reassignment (Rames)
- clarify the XSS-escaping comment (both < and / escaped so no </script>
  sequence can form) (Miga #1)

* feat(telemetry): unify CLI and Studio PostHog identity (Layer 1)

Seed the CLI's anonymous distinct_id into Studio at launch so a developer's
CLI and their Studio browser session resolve to the same PostHog person.
Also unifies Studio's two previously-independent anonymous ids into one
source of truth. Uses only the existing anonymous machine id (no new PII).

- cli: inject window.__HF_CLI_DISTINCT_ID into the served index.html <head>
  (mirrors the existing __HF_STUDIO_ENV__ injection) + add a fallback
  GET /api/telemetry-identity endpoint. Only seeds when CLI telemetry is
  enabled; empty/no-op otherwise.
- studio: new telemetry/distinctId.ts single source of truth; adopts the
  CLI-seeded id when present, else falls back to the existing per-browser
  localStorage id. Both Studio clients (studio:* and studio_*/render) now
  share this one id.

* fix(telemetry): keep Studio distinct_id resolver fail-silent on getItem

resolveStudioDistinctId read localStorage.getItem() outside a try/catch
while every other external access in the module is guarded. In a
storage-restricted context where the localStorage reference resolves but
getItem throws, the resolver threw — breaking the module's fail-silent
contract (telemetry must never break Studio). Guard the reads and treat a
throw as "no id". Also drop an unnecessary `as` cast in the test per the
repo CLAUDE.md convention (the optional global is already declared).

* refactor(telemetry): address review feedback on identity unification

- dedup safeLocalStorage/safeSessionStorage into utils/safeStorage.ts,
  used by both telemetry/config.ts and telemetry/distinctId.ts (Miga #6)
- replace redundant `??=` with `=` in the no-storage branch; cachedId is
  guaranteed null there (Miga #2)
- extract buildStudioHeadScripts() so the "identity script before env
  script" head-injection ordering is a pure, tested invariant (Miga #5)
- add tests: head-script ordering + telemetry-off passthrough, and a
  Studio memoization test proving an adopted CLI id survives a later
  window.__HF_CLI_DISTINCT_ID reassignment (Rames)
- clarify the XSS-escaping comment (both < and / escaped so no </script>
  sequence can form) (Miga #1)

Blockers:
- heygen-com#2: late_init_set false positive on fractional opacity (0.5 matched as 0)
  Fixed: /opacity\s*:\s*0(?![.\d])/ negative lookahead
- heygen-com#3: scene-1 prefix skip matches scene 10+ (s1- matches s10-)
  Fixed: extract full number and compare exactly

High severity:
- heygen-com#4: autoAlpha not covered by late_init_set
  Fixed: checks both opacity and autoAlpha
- heygen-com#5: al() crashes on non-hex colors (#fff shorthand, rgb(), null)
  Fixed: guard + shorthand expansion + NaN fallback
- heygen-com#6: "Full palette" with null bg crashes isDark
  Fixed: null guard defaults to dark
- heygen-com#7: template literals missed by tl_from_in_multiscene
  Fixed: regex includes backtick quotes

Medium:
- heygen-com#9: no retry limit on eval failures → infinite loop
  Fixed: max 2 retries, then escalate to user
- heygen-com#10: vague ID convention
  Fixed: explicit s{N}- prefix rule in multi-scene.md
- heygen-com#11: visual-style.md backward compat
  Fixed: Step 0b checks both filenames
- heygen-com#13: preview_html script injection
  Fixed: documented prohibition in design-picker.md

… helper, boundary tests

- de_worker_inversion is now a tri-state string ("inverted" | "reverted" |
  "none") instead of a boolean: the self-verify retry marks the render
  "reverted" rather than resetting to false, so the dashboard can segment
  the lost-inversion cohort first-class instead of inferring it from
  deSelfVerifyFallback + frame-count joins (james-russo #1).
- The retry rollback is extracted to resolveInversionRetryPlan (pure,
  exported) with unit coverage: pre-inversion worker-count restore,
  streaming re-resolution (multi-worker retry -> disk), "reverted" state,
  null when never inverted (james-russo #2).
- WOULD_RESOLVE_MULTI_WORKER named constant replaces the bare sentinel 2
  (james-russo #5); minFrames: -1 boundary case added (miga #3).

94/94 renderOrchestrator tests; tsc/oxlint/oxfmt clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

…reaming over auto-parallel (#2026)

* feat(producer,cli): drawElement priority inversion — single-worker streaming over auto-parallel

clamp:parallel eats 50% of local renders (1,326/fortnight; DE engagement
stuck at 3.8%) by routing multi-worker renders to unverified screenshot
capture. Benchmarks (2026-07-08, 4 comps x W1/W2/W3/W5) show that above the
~900-frame amortization crossover, single-worker VERIFIED drawElement
streaming beats screenshot-parallel at EVERY worker count (2,380f: 66s vs
109-127s; 3,600f: 33s vs 39-56s; parallel scaling flattens past W2), while
below it DE's fixed init cost loses by <=2.2s.

- shouldPreferSingleWorkerDrawElement (exported predicate + 7 unit tests):
  inverts an AUTO-resolved multi-worker render to workerCount=1 when the
  comp matches the benchmarked configuration — default-on DE (darwin
  hardware clamp upstream), no compile gate, no forced-screenshot hint,
  mp4 output, single-worker streaming eligible, and totalFrames >=
  HF_DE_SINGLE_MIN_FRAMES (default 900; 0 disables). Explicit --workers N
  is always honored.
- Inverted renders keep the probe session and land on the worker-encode
  streaming drain — the ONLY path with runtime self-verification, so this
  moves ~40% of previously-clamped renders onto the verified fast path.
  Comps that later hit an init-time gate (~1.5% of local renders) render
  single-worker screenshot streaming; accepted trade.
- Telemetry: de_worker_inversion on render_complete (orchestrator ->
  perfSummary.workerInversion -> CLI), plus the worker_resolution
  observability checkpoint now records deWorkerInversion.

Validation: e2e matrix on 2,381f comp — auto->5 workers inverted to 1,
DE verified 4x inf PSNR, RENDER_OK; short comp (360f) auto stays 5-worker;
explicit WORKERS=3 honored; HF_DE_SINGLE_MIN_FRAMES=0 disables. Canary
suite 7/7 (PSNRs identical). renderOrchestrator tests 86/86.
tsc/oxlint/oxfmt clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(producer): review fixes — inversion routing guards, calibration skip, retry revert

Max code-review round on the inversion (13 confirmed findings):

- Streaming spawn-failure disk fallback now clamps default-on drawElement
  (deClampReason=disk_path, DE-mode probe closed) exactly like the
  pre-capture clamp — previously it carried useDrawElement=true onto the
  unverified disk path, the hole the verified-path confinement exists to
  close, newly reachable for every inverted render.
- Predicate gained the routing knowledge it was blind to: layered/HDR and
  shader-transition comps (drawElement never runs there), supersampling
  (deviceScaleFactor>1 init gate), a probe session whose init gates already
  disengaged DE, and the PRODUCER_EXPERIMENTAL_FAST_CAPTURE=true explicit
  parallel-DE opt-in (honored like --workers N).
- Eligibility is evaluated BEFORE capture calibration and skips it when the
  inversion pins workers to 1 regardless of the estimate — the throwaway
  calibration browser + sample captures cost ~41s on the 2,381-frame
  benchmark comp (auto render: 111.6s -> 70.1s total).
- Self-verify retry reverts the inversion: the re-render returns to the
  pre-inversion parallel screenshot path (disk) instead of single-worker
  screenshot streaming, the slowest shape for exactly the comps drawElement
  damages.
- HF_DE_SINGLE_MIN_FRAMES="" (set-but-empty) now falls back to the 900
  default instead of aliasing the 0 kill switch.
- Timeout advisory uses the RESOLVED worker count — an inverted render that
  times out no longer prints "Retry with --workers 1" (the configuration
  that just failed).
- Telemetry: deWorkerInversion recorded in capture observability (failed
  renders are attributable), emitted as literal false when not fired
  (queryable denominator), and the drawElement perf input shape is one
  exported DrawElementPerfInput type instead of three copies.
- Tests: requestedWorkers undefined (the value production actually passes)
  + the four new predicate guards; 91/91.

Validation: e2e auto render — calibration skipped (deInversionEligible),
inversion fires, DE verified 4x inf, total 70.1s (was 111.6s);
HF_DE_SINGLE_MIN_FRAMES=0 restores calibration + parallel; canary suite
7/7 (PSNRs identical); tsc/oxlint/oxfmt clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(producer,cli): review round 2 — loss-cohort telemetry, retry-plan helper, boundary tests

- de_worker_inversion is now a tri-state string ("inverted" | "reverted" |
  "none") instead of a boolean: the self-verify retry marks the render
  "reverted" rather than resetting to false, so the dashboard can segment
  the lost-inversion cohort first-class instead of inferring it from
  deSelfVerifyFallback + frame-count joins (james-russo #1).
- The retry rollback is extracted to resolveInversionRetryPlan (pure,
  exported) with unit coverage: pre-inversion worker-count restore,
  streaming re-resolution (multi-worker retry -> disk), "reverted" state,
  null when never inverted (james-russo #2).
- WOULD_RESOLVE_MULTI_WORKER named constant replaces the bare sentinel 2
  (james-russo #5); minFrames: -1 boundary case added (miga #3).

94/94 renderOrchestrator tests; tsc/oxlint/oxfmt clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* feat(producer,cli): emit de_pre_inversion_workers for the parallel counterfactual

The ramp-down decision needs "did DE beat the parallel render it displaced",
not just "did DE beat single-worker screenshot". Emitting the worker count
the auto-resolution chose BEFORE the inversion pinned it to 1 makes the
parallel counterfactual computable per render (screenshot ms/frame from the
verify samples / W x the measured parallel-efficiency curve). Set only when
the inversion fired.

Smoke: 2,381f auto render -> de_worker_inversion="inverted",
de_pre_inversion_workers=5, mode=drawelement, verify armed 4. 99/99 tests.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

## What

Fixes five reported false-positive/false-negative patterns in the WCAG contrast audit (`hyperframes validate --contrast`):

1. **SVG fill vs. text color** — foreground read from CSS `color` instead of SVG `fill`.
2. **Cross-component color bleed** — background estimate bleeds into a neighboring panel/layer.
3. **Backdrop-filter glass text** — background estimate misses the blur/tint and reads the raw backdrop.
4. **Partially-overlapping translucent decoration** — a decorative shape inside or partly touching the text's bbox goes undetected.
5. **Solid-fill pill/button** — investigated, did **not** reproduce; already handled correctly by the existing own-background ancestor walk. Not touched.

## Why

The audit estimated an element's background two ways:
- foreground: always `getComputedStyle(el).color` — wrong for SVG `<text>`/`<tspan>`, which is painted via `fill`, an independent CSS property.
- background: a 4px pixel ring sampled just **outside** the text's bounding box, with a fallback to an ancestor's opaque `background-color` for solid pills/buttons.

The ring is a proximity heuristic. It's wrong whenever what's immediately outside the text differs from what's actually behind it:
- text near the edge of its own panel, with a differently-colored sibling panel/layer just past the bbox — the ring samples the neighbor.
- a `backdrop-filter: blur()` glass panel sized only a couple pixels larger than the text — the ring exits the panel into the raw, unblurred, untinted backdrop.
- a translucent decoration that only partially overlaps the ring, or sits entirely **inside** the bbox — invisible to the ring regardless of size.

## How

**SVG fill (#1):** elements inside an `<svg>` (`el.ownerSVGElement`) now prefer the computed `fill` when it resolves to a solid `rgb()`/`rgba()` color, falling back to `color` for paint values that aren't a plain color (`none`, `context-fill`, gradient/pattern refs).

**Cross-comp bleed / glass blur / partial decoration (#2–#4):** replaced the ring-sampling + own-background-ancestor-walk heuristic with a two-phase capture:
1. `__contrastAuditPrepare()` walks the DOM, computes each candidate's foreground (unchanged logic from #1), and **hides that element's own text paint** (`color`/`fill` → `transparent`, layout-neutral — no reflow).
2. The caller takes **one** screenshot with the glyphs invisible (same number of screenshots as before — just moved after the hide instead of before it).
3. `__contrastAuditFinish(imgBase64, time, candidates)` restores the original paint immediately, then samples the **real composited pixels directly inside each element's own bbox** — no proximity heuristic needed, since these are the exact pixels that were behind the glyphs.

This is a real architectural change to `contrast-audit.browser.js`'s calling contract (single `__contrastAudit` → `__contrastAuditPrepare`/`__contrastAuditFinish`), with `validate.ts`'s `runContrastAudit` updated to match, including a try/finally restore-safety-net so a mid-loop screenshot/decode failure can't leave a later sample auditing a page with stale hidden text.

Mirrored the identical change in `skills/hyperframes-creative/scripts/contrast-report.mjs`, which duplicates the same DOM-walk/sampling logic (not just the WCAG math). There, the **visible** frame for the human-facing overlay image still comes from the producer's normal `captureFrameToBuffer` path (unchanged); only the **background-sampling** capture is a plain `session.page.screenshot()` taken after hiding text — deliberately bypassing `captureFrameToBuffer`, whose static-frame dedup cache knows nothing about the DOM mutation and would hand back a stale pre-mutation buffer.

**Solid-fill pill (#5):** reproduced a rounded pill/button with a busy page background outside it. The existing own-background ancestor walk already resolves the pill's declared `background-color` correctly regardless of the rounded corners — confirmed via repro, both before and after this change report the identical (correct) result. No fix needed; left untouched, and this case is covered by the new architecture too (would give the same right answer even without the ancestor-walk fallback).

Added `packages/cli/src/commands/contrast-sample.ts` (mirroring the existing `contrast-bg.ts`/`contrast-fg.ts` pattern) hosting the pure sample-rect/grid-point computation, unit tested — the browser-injected scripts can't import it directly, so it's kept in sync by hand, same convention as the rest of this file.

## Test plan

- [x] Unit tests: `contrast-fg.test.ts` (SVG fill resolution), `contrast-sample.test.ts` (sample-rect clamping/degenerate cases), plus the full `packages/cli` suite (1424 tests) passes, including an updated `layout-audit.browser.test.ts` case that called the old single-function `__contrastAudit` API directly.
- [x] Manual verification — standalone `puppeteer-core` harness against real `chrome-headless-shell`, one minimal HTML fixture per pattern, comparing the audit's reported ratio/verdict against a hand-constructed ground truth:
  - **SVG fill**: `fill:white` / no `color` on black bg → before: `fg=rgb(0,0,0)` ratio `1:1` (false FAIL); after: `fg=rgb(255,255,255)` ratio `21:1` (correct PASS).
  - **Cross-comp bleed**: text on a black sibling highlight box 2px larger than the text, white page bg outside it → before: `bg=rgb(255,255,255)` ratio `1.23:1` (false FAIL); after: `bg=rgb(0,0,0)` ratio `17.14:1` (correct PASS).
  - **Glass blur**: black text on an 18%-white-tinted `backdrop-filter: blur(14px)` panel over a yellow/blue gradient, panel only ~2px larger than the text → before: `bg=rgb(0,64,255)` (raw gradient color, blur/tint completely missed) ratio `3.18:1` (false FAIL); after: `bg=rgb(159,160,165)` (correct blurred/tinted blend) ratio `8.05:1` (correct PASS).
  - **Partial decoration**: text 92%-covered by a translucent white badge on a dark bg → before: `bg=rgb(16,16,16)` (ring never touches the badge, which sits entirely inside the bbox) ratio `17.45:1` (false PASS); after: `bg=rgb(171,171,171)` (correctly detects the badge) ratio `2.11:1` (correct FAIL).
  - **Solid pill sanity**: unaffected — `bg=rgb(10,10,10)` ratio `19.8:1` before and after.
- [x] End-to-end: ran the actual `hyperframes validate --contrast` CLI command (via `tsx src/cli.ts`) against a real scaffolded project containing all 4 patterns simultaneously — only the genuinely-failing case (the 92%-covered decoration) is reported (`1.09:1`, need `3:1`); the cross-comp-bleed, glass-blur, and solid-pill cases are correctly silent. A second vanilla scaffold with plain white-on-dark text produces zero false positives.
- [x] `oxlint`, `oxfmt --check`, and `tsc --noEmit` all pass on the changed files.

Field signal ts=1784040753 (#hyperframes-cli-feedback): a composition
with ~40 heavy overlay DOM elements — `filter:blur`, oversized
`radial-gradient`, and `clip-path` animations — captures solid-black for
the first ~half of the render, recovering near the end. Reproduces
identically via drawElement AND forced --no-browser-gpu screenshot
capture AND `snapshot`, so the capture layer itself is the offender, not
encoder/mux. Independent of duration (padding the timeline grows the bad
zone proportionally, doesn't shift it). Presence alone matters — even
opacity:0 / visibility:hidden / unused overlays contribute. Reporter's
workaround was splitting into per-transition mini-compositions +
FFmpeg concat.

Add compositionCheck rule `composition_heavy_overlay_count_high`
(warning). Counts DOM elements that carry any of: inline
`style` filter:blur / clip-path (non-none) / radial-gradient, or a
class/id whose top-level CSS rule body sets one of those. `display:none`
elements are counted-out (removed from render tree); opacity:0 /
visibility:hidden overlays are counted-in per the field-signal repro
shape. Warns at 25 to give lead time before the observed 40-element bad
zone. Skips registry source and installed-block files, mirroring
`composition_file_too_large`. Includes a `ts=1784040753` reference in
fixHint so authors can trace the risk shape.

Stack: PR heygen-com#5 of 9 (base via/parity-telemetry-gate).

Signed-off-by: Via

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