test(skills): pin the catalog exemption as a capability and lint the templates list

[miguel-heygen]

Why

Two follow-ups from the review of #3829.

1. The two skills exempt from the catalog search (embedded-captions, talking-head-recut) were pinned only by the sentence that declares the exemption. The exemption is a capability claim, so the moment either skill gains a way to install a registry item, the sentence would be wrong and nothing would fail.
2. The templates list in the CLI scaffold reference says it is lint-checked, but the file lacked the marker that arms the registry-snapshot lint, so a misspelt template name passed. That is the drift class the lint exists to catch.

What changed

• The content test now also asserts that no file in either exempt skill contains an install command or a registry path. data-composition-src is deliberately not the signal: talking-head-recut mounts its own chapters with it, which is not a registry item.
• The scaffold reference carries the registry-items marker, with its size presets and skill names allowlisted as legitimate non-items.
• Skills manifest regenerated for the doc change.

Verification

• Content test: 13 passed. Appending hyperframes add caption-glitch-rgb to an exempt skill's catalog doc fails the test.
• Skill lint: 32 files and 7 snapshots checked against 408 registry items, no issues. Misspelling nyt-graph as nyt-graphs in the templates list fails the lint.
• Manifest in sync, mirror unchanged.

[terencecho]

APPROVE at 3b7dc6b8abb38966ca74e12105b5c5f71e871540. Test + docs follow-up that turns both #3829 follow-up notes into enforceable tripwires.

Author + head. Sole commit by miguel-heygen. 3 files, +20/-7. mergeStateStatus=BLOCKED (missing approval), mergeable=MERGEABLE.

1. Exemption inverse-invariant test (coreSkillContent.test.ts:190-207).
New helper skillTextFiles(dir) recursively enumerates every .md|.mjs|.cjs|.js|.ts|.json|.html file in a skill directory. For each of the two exempt skills (embedded-captions, talking-head-recut) the test iterates every text file and asserts:

expect(readFileSync(file, "utf8")).not.toMatch(/hyperframes add\b|registry\/(blocks|components)\//);

A planted hyperframes add or a registry/blocks/… / registry/components/… path in either exempt skill's directory now fails the test with the offending file cited. Turns the FU-2 capability claim into a load-bearing invariant.

Deliberate omission — data-composition-src is NOT in the ban regex. Miguel's comment explains: talking-head-recut mounts its own chapters with it (card-timeline chunking, not registry mount), so banning it would false-positive. Ban regex is precise, not over-broad.

The \b after add correctly ensures hyperframes address / hyperframes added don't match. The alternation with registry/(blocks|components)/ catches direct path references to registry-item paths.

2. Init-and-scaffold.md lint marker (skills/hyperframes-cli/references/init-and-scaffold.md:3).
Adds <!-- registry-items: allow=blank,landscape-4k,portrait-4k,square-4k,product-launch-video,hyperframes-core,media-use --> — covers the file's Templates list. blank (CLI-hardcoded, not a registry item) explicitly allowlisted alongside the four *-4k presets and three registry examples. A misspelt template in the file now fails the lint with file+line+id per Miguel's tripwire proof on #3829. Closes the exact doc/lint asymmetry I flagged (self-claim of "checked by lint" without the marker).

3. skills-manifest.json. Hash regenerated to match the init-and-scaffold.md change. Mechanical.

Scope. Docs + tests only. No engine/runtime/studio touch. No test removals.

Reviews at head. Empty.

CI. BLOCKED reflects the missing approval; check green-state expected to match #3829's shape (skills lane, no runtime touch).

— tai