fix(vibe): Exempt Start Here stories from the v1.0 freeze

[shafty023]

Exempts story files titled under the Storybook's Start Here/ root from the v1.0 freeze in handoff-inventory.mjs (design ruling, 2026-10-06).

1.0.33 froze every story file that was v1.0 at the base, including Start Here/Version History. symphony-alpha's apps/storybook/TAXONOMY.md makes any story add, move or removal a Storybook release with a Version History entry in the same change, so the freeze blocked every Storybook-changing handoff (seen on session grouped-list-sections). Start Here is unversioned (.storybook/manager.ts, UNVERSIONED_ROOT_ID = "start-here"), so a tag there is not a version claim.

• handoff-inventory.mjs: a story file whose meta title's first segment is Start Here, at the base or now, is left out of v1Stories (freeze, title and tag checks) and retitledStories. Based on the title root, not a file name. Every other v1.0 file stays frozen with the compile-only exception.
• guardrails.md, vibe-storybook-decomposer step 4 and the handoff SKILL Storybook paragraph each state the exemption in one line.
• Node test: editing Version History's content and changing its tag from v1.0 to v2.0, plus a retitle within Start Here, pass; a v1.0 edit outside Start Here still blocks as frozen. New contract test test_vibe_start_here_unversioned_contract.py. Both fail on 1.0.36 (node test: the Start Here files land in v1Stories; contract: 5 of 5 fail).
• Bumps vibe to 1.0.37 in both manifests with a CHANGELOG entry.

uv run pytest plugins/vibe: 188 passed. Vibe node tests: 285 passed. ruff check . and pyright clean.