fix(skill): w2h enforcement round 2 — close the deeper shirking patterns

A second agent debrief (different session, with the prior enforcement edits
applied) revealed the most damning failure yet: the agent used 1 of 65
captured assets. They wrote their own "Asset Audit" table saying SKIP for
64 hero illustrations, brand SVGs, and signature visuals. The entire point
of capture is to USE the brand's assets — that gate was bypassed entirely.

The debrief also revealed 5 other patterns the prior enforcement missed.
This commit closes all 6.

**Pattern A — Asset Audit gate (step-3-storyboard.md)** — BIGGEST FIX

Adds a non-skippable Asset Audit section in Step 3 that requires viewing
every page of capture/assets/contact-sheet-*.jpg + svgs/contact-sheet-*.jpg,
pasting 5 distinctive assets per page (with descriptions of what's actually
pictured), and choosing USE/SKIP per asset with one-sentence justification
for each SKIP. Brand-defaults floor: at least one beat MUST use a captured
hero illustration/photograph/signature diagram — not just the logo. The
forbidden list explicitly calls out: reading asset-descriptions.md alone
without opening the contact sheets, and rebuilding signature graphics in
CSS when the brand's own SVG of that graphic is in capture/assets/.

**Pattern B — Auto mode scope (SKILL.md + step-2-brief.md)**

Clarifies that auto mode covers user-PREFERENCE gates (TTS provider,
voice, beat count, captions yes/no — where the agent decides on the
user's behalf) but NOT quality-VERIFICATION gates (Asset Audit, per-beat
HTML read, DoD checklist, honest disclosure). Adds explicit test for
distinguishing: if the answer changes the content of the video, it's a
preference; if the answer is "did the verification happen?", it's a
quality gate. The agent that skipped the captions question by reasoning
"auto mode says bias toward action" was misusing auto mode.

**Pattern C — 3-path audio/motion verification (step-6-validate.md)**

Replaces the prior "Path 1 or explicit deferred" with three explicit
paths: (1) Play preview in Playwright, (2) render low-res MP4 and read
frames at ≥5fps, or (3) explicit deferred disclosure with QUANTIFIED
coverage gap ("18/900 frames = 2% coverage"). The percentage in Path 3 is
mandatory — vague "deferred to user" was the loophole. Forbidden: claiming
"confirmed via snapshot" as audio/motion evidence; 18 PNGs from a 900-
frame video is 2% coverage, not verification.

**Pattern D — Sub-agent diagnoses are hypotheses (beat-builder-guide.md)**

When a sub-agent reports "this is a linter false positive" / "this is a
known bug", that is a HYPOTHESIS from one symptom — not a verified
finding. Before propagating the workaround to other beats, main agent
must EITHER read the source to confirm OR explicitly disclose the
unverified claim. The debrief showed the main agent applied beat-2's
"linter false positive" diagnosis to beat-4 without ever reading
packages/core/src/lint/utils.ts to confirm.

**Pattern E — Re-snapshot after parallel sub-agents (step-5-build.md)**

When sub-agents run in parallel, each snapshots a project where sibling
beats may not exist yet. Their snapshots at beat boundaries or during
shader transitions show the WRONG content (typically previous beat).
Required after all complete: a canonical project-wide snapshot via the
CLI — that's what Step 6's DoD uses. Sub-agents' intermediate snapshots
are sanity checks, not the deliverable.

**Pattern F — STORYBOARD.md must be updated when divergence accepted
(beat-builder-guide.md)**

When a sub-agent diverges from spec ("the real brand mark is lowercase
'huly' not uppercase 'HULY'") AND the main agent accepts the divergence,
the main agent MUST patch STORYBOARD.md to reflect reality. Otherwise
the spec lies and the next session reading it as ground truth gets the
wrong information. Examples covered: brand mark casing, cell size at
scale, SFX timing alignment.

6 files changed, +131/-11 (net +120 lines of enforcement).
Format checks pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

skills/website-to-hyperframes/references/beat-builder-guide.md

@@ -156,6 +156,29 @@ FLAG: STORYBOARD.md beat 3 says "Row 1 transitions blue → orange at 3.5s" but
 
 The main agent then confirms or corrects before Step 6 advances. Picking an interpretation silently means the build looks "fine" while diverging from intent — and the user only notices in motion.
 
+### Sub-agent diagnoses are unverified claims, not facts
+
+When a sub-agent reports "this is a linter false positive" / "this is a known bug" / "this attribute doesn't work as documented" — those are HYPOTHESES, not findings. Sub-agents diagnose from one symptom; they don't have repo-wide context.
+
+Before propagating any sub-agent diagnosis (e.g., applying the same "workaround" to another beat, or telling the user "this is a known bug"), do ONE of:
+
+1. **Verify by reading the source.** Open the file the sub-agent claims is buggy. Confirm the bug exists. Example: "I read `packages/core/src/lint/utils.ts:42` and confirmed the regex matches `url(\"data:image/svg+xml...\")` incorrectly. The workaround is to base64-encode the URI."
+2. **Disclose the unverified claim.** Don't suppress it — surface it. Example: "Sub-agent for beat 2 diagnosed `root_missing_composition_id` as a linter false positive on inline SVG data URIs. I applied the same workaround to beat 4 WITHOUT verifying the underlying claim. Worth filing as a regression against `packages/core/src/lint/utils.ts` to confirm."
+
+**Forbidden:** silently adopting the workaround pattern and presenting "lint passes" as evidence. If the workaround came from an unverified diagnosis, "lint passes because the diagnosis was correct AND I worked around it" and "lint passes because the diagnosis was wrong but the workaround happened to make the symptom disappear" are both possible. Without verification, you don't know which. The next session inherits the workaround AND the unverified diagnosis.
+
+### When you accept a sub-agent's divergence from spec — UPDATE the spec
+
+If a sub-agent reports "I diverged from STORYBOARD.md because..." AND you accept the divergence, you MUST update STORYBOARD.md to reflect the actual implementation. Otherwise the spec lies about the artifact.
+
+Examples:
+
+- Sub-agent: "Storyboard says 'HULY' uppercase but the actual logo asset is lowercase 'huly'. I used lowercase." Accept → edit STORYBOARD.md beat N to say "huly" lowercase. Note the change inline.
+- Sub-agent: "Storyboard says cells at 56px but they read too small at 1920×1080. I used 96px." Accept → edit STORYBOARD.md beat N's cell size to 96px.
+- Sub-agent: "Storyboard says SFX at t=4.7s but the visual moment lands at t=5.2s; I aligned SFX to the visual." Accept → edit STORYBOARD.md SFX line to t=5.2s.
+
+**Forbidden:** accepting the divergence silently and leaving the storyboard with the wrong spec. The next session reading STORYBOARD.md will trust it as ground truth. The spec is a contract; if you break the contract, update the contract.
+
 ---
 
 ## Continuous motion — the most important rule