fix: make registry blocks pass lint errors

[miguel-heygen]

Problem

Closes #559.

The catalog flowchart block emitted HyperFrames' own template_literal_selector lint error out of the box after hyperframes add flowchart. After the registry cleanup pass, the installed block also still carried the composition_file_too_large warning, so the issue repro was not fully lint-clean for users.

What this fixes

• Rewrites flowchart selector construction from template interpolation to explicit string concatenation.
• Adds data-start="0" to registry block roots that were missing it.
• Adds class="clip" to invisible driver elements that already carry timing attributes.
• Initializes window.__timelines before ui-3d-reveal registers its timeline.
• Stamps installed registry block compositions with a harmless provenance comment.
• Skips only the large-file advisory for registry source blocks and registry-installed blocks, while keeping the warning for plain user-authored large compositions.
• Re-runs the registry and installed-flowchart lint passes with no Catalog block flowchart triggers HF lint rule template_literal_selector #559 lint errors or file-size warnings.

Root cause

flowchart used a hardcoded selector constant but then interpolated it through template literals, which still trips template_literal_selector. Separately, registry catalog files are curated distribution artifacts; treating those source or installed third-party blocks exactly like user-authored compositions made the 300-line authoring advisory show up for content users did not write.

Verification

Local checks

• Full registry block source scan through lintHyperframeHtml(..., { isSubComposition: true }) -> files=39 composition_file_too_large=0 errors=0
• Fresh /tmp/hf-flowchart-installed-qa project using a local registry server, then hyperframes add flowchart and hyperframes lint -> 0 errors, 0 warnings
• Installed compositions/flowchart.html starts with <!-- hyperframes-registry-item: flowchart -->
• bun run --filter @hyperframes/core test src/lint/rules/composition.test.ts -> 36 passed
• bun run --filter @hyperframes/cli test src/commands/add.test.ts -> 11 passed
• bun run lint
• bun run --filter @hyperframes/core typecheck
• bun run --filter @hyperframes/cli typecheck
• bun run build:hyperframes-runtime
• bunx oxfmt --check on changed files
• git diff --check
• Pre-commit hook passed for the committed files.

Browser verification

• Created /tmp/hf-flowchart-qa embedding the patched flowchart.html.
• Opened Studio at http://localhost:5194 with agent-browser.
• Played the flowchart timeline and verified the block renders without browser errors.
• Screenshot: qa-artifacts/issue-559/flowchart-2s.png
• Recording: qa-artifacts/issue-559/flowchart-playback.webm

Notes

The large-file advisory still applies to plain user-authored compositions over 300 lines. The exemption is limited to registry source files shaped like registry/blocks/<block>/<block>.html and installed block files carrying the registry provenance marker.

[jrusso1020]

LGTM — addresses both issue #559 (flowchart template-literal selectors) and the registry-block false-positive concern I flagged on #523.

Two-pronged exclusion strategy for composition_file_too_large / timeline_track_too_dense:

1. Path-based skip when filePath matches registry/blocks/<name>/<name>.html — for hyperframes-oss source files
2. Magic-comment marker <!-- hyperframes-registry-item: <name> --> injected by the installer when fetching block composition files; lint rule scans first 512 bytes for this marker

This is the right shape — durable across moves, explicit, and survives copy-paste of installed blocks. Test coverage in composition.test.ts exercises both paths (source skip, installed skip, normal file warn) and add.test.ts verifies the marker is actually injected during install.

Issue #559 fix: flowchart.html and 18 sibling registry blocks updated to add data-start="0" on roots, class="clip" on timed elements, and most importantly the flowchart block swaps `${S} #node-X` template literals for S + " #node-X" string concatenation. Net: registry blocks are now lint-clean out of the box.

Tests: @hyperframes/core 563/563 + @hyperframes/cli 180/180 pass.

— Review by Rames Jusso