[xuanruli]

What

The switch from #6396 that leaves out contrast failures measured mid-animation moves from a CLI flag and an
environment variable to a field in HF_TOOL_CONTEXT:

{ "version": 1, "capabilities": { "check-review": { "skipContrastInMotion": true } } }

• Removed: --skip-contrast-in-motion and HYPERFRAMES_CHECK_SKIP_CONTRAST_IN_MOTION.
• Added: a check-review capability parsed by readToolContext(). Its only field for now is
  skipContrastInMotion. A value that is not true is off, and unknown fields are ignored.
• The motion rule itself (contrastMotion.ts, the in-page read in checkBrowser.ts) is unchanged.

Without the capability, check output is byte-identical to today's.

Why

This switch is for harnesses that show check output to an agent, not for people at a terminal. As a flag it added
a row to hyperframes check --help, to the CLI docs and to the hyperframes-cli skill, so every terminal user and
every agent reading the skill saw an option meant for one kind of caller. HF_TOOL_CONTEXT is the documented
interface a harness already uses to tell the CLI what it can do (events, project-lock), so any harness can opt
in there and the CLI surface and skills stay as they were before #6396.

Related work

Follow-up to #6396 (merged as afdad4e). #6401, stacked on this one, adds a second check-review field, findingFrames.

How

• toolContext.ts: ToolContext.checkReview and parseCheckReview, next to the existing events and
  project-lock parsers.
• check.ts: parseCheckOptions reads readToolContext().checkReview?.skipContrastInMotion instead of the
  flag and env var. The flag definition and the envFlagEnabled import are gone.
• Docs: a check-review section in docs/developers/harness-tool-context.mdx. In docs/packages/cli.mdx the
  flag-table row is removed and the paragraph about the rule now points at the capability.
• Skills: feat(cli): opt-in check flag that leaves out contrast measured mid-animation #6396's line in skills/hyperframes-cli/references/lint-validate-inspect.md is reverted, and
  skills-manifest.json goes back to the pre-feat(cli): opt-in check flag that leaves out contrast measured mid-animation #6396 hash for hyperframes-cli.

Test plan

• Unit tests updated: check.test.ts turns the switch on through HF_TOOL_CONTEXT instead of the flag;
  toolContext.test.ts covers parsing check-review fields as booleans that default to false.
• vitest run src/commands/check.test.ts src/utils/toolContext.test.ts src/utils/contrastMotion.test.ts src/utils/checkBrowser.test.ts
  in packages/cli: 4 files, 210 tests passed.
• tsc --noEmit in packages/cli: clean.
• oxlint and oxfmt --check on the changed files: clean. gen:skills-manifest --check: in sync.
  scripts/lint-skills.ts and check-skill-mirror.mjs: no issues.
• Documentation updated.
• Comments follow CONTRIBUTING.md "Comments".

Not covered

• No manual end-to-end check run on this commit; the motion rule's code is the same as feat(cli): opt-in check flag that leaves out contrast measured mid-animation #6396's, which was
  exercised there.
• A terminal user who wants this behaviour now has to set HF_TOOL_CONTEXT by hand.

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[github-actions]

Edit accuracy: accurate 271 (base branch 271), smooth 137 of those

The gate passes.
Smoothness is reported in the artifact, not gated. A case fails only if it fails 2 of 3 runs.

Quarantined, measured but not gated (0)

[heygengenesis]

Verdict: APPROVE · 0 blocker · 0 important · 0 nits · head 8153246

Scope

• Parsing: parseCheckReview sets the switch only on strict === true. A non-object capability (including an array) is dropped, a missing field or a field that is not true (1, "1") is false, and unknown fields are ignored. Bad JSON or a wrong version still returns {}.
• events/project-lock: the parsers and return spreads are unchanged. projectLock.ts still reads its own readToolContext(). Without check-review the returned object is the same as before, so the existing toEqual cases still hold.
• Propagation: parseCheckOptions is the only producer of skipContrastInMotion. checkPipeline.ts:607 and checkBrowser consume it unchanged. A grep finds no remaining references to the flag or the env var.
• Default output: with no capability the key is absent, the same as base with the flag off.
• Compat: #6396 (afdad4ea3) is in no release tag (v0.8.201 predates it), so removing the flag and env var breaks no shipped interface. The skills/hyperframes-cli/ tree matches afdad4ea3~1, and the manifest hash is back to 08a4a3a815d71988.
• CI: every workflow on this head passed, including required Typecheck, Test, Windows, Skills manifest and edit-accuracy gate.