deploy: make vanilla aem-boilerplate the runtime; remove AuthorKit

[paolomoz]

Why

stardust:deploy assumed the AuthorKit runtime by default and treated vanilla aem-boilerplate as a "port AuthorKit onto it" branch (a 55-line bootstrap section + bootstrap-authorkit.mjs). Two things the end-to-end interview sessions made clear:

1. Operators already go vanilla off-script and it works. Multiple sessions deliberately skipped AuthorKit and shipped full sites (one cited 95 pages + fragments; the multi-site test covered 8 sites). The skill's "vanilla path" wasn't vanilla — it converted vanilla into AuthorKit.
2. AuthorKit is the source of most silent-failure guardrails (no .block class → grids silently stack; footer double-load; postlcp className edit; body.appear blank-render; fragment-<script> inert; late-fragment CLS), and its upstream runtime has drifted off the static-fragment model the skill documents. Maintaining a stale runtime contract is the worst option.

This PR makes vanilla the first-class (and only documented) target and demotes AuthorKit to a short legacy appendix. (Assumes no actively-maintained live AuthorKit sites depend on the skill — confirmed out-of-band.)

What changed

deploy/SKILL.md

• Runtime section replaces the AuthorKit bootstrap: a one-line runtime-detection gate + legacy appendix. Records runtime: aem-boilerplate as state so prototype/migrate/diff key the class contract off a declared field instead of re-guessing (addresses the prototype↔deploy contract-drift the sessions flagged).
• Sections: .default-content-wrapper (not .default-content/.block-content); main > .section:empty{display:none} to collapse the consumed metadata section; grounds set per-block via block.closest('.section').
• Fonts: metric-matched fallback @font-face + the standard body.appear paint gate vanilla actually drives — drops body.session/decorateSession; inverts the old feat: add workflow-purge skill and fix launcher eventType bitmask #40 warning.
• Buttons: vanilla decorateButtons → .button/.button-container/.primary/.secondary (drops .btn/.btn-group/ak.js decorateButton).
• Header/footer: self-contained header/footer blocks — block JS runs, so no inert-<script> trap, no postlcp className edit, no late-fragment CLS. Adds a subfolder multi-tenant note (don't hardcode a root-absolute nav source).
• Updated the anti-patterns, Local-QA, multi-view SPA, and per-page checklist to match.

Scripts

• Deleted bootstrap-authorkit.mjs (obsolete).
• build-harness.mjs now loads /scripts/scripts.js (vanilla boot) instead of /scripts/ak.js.

Other skills

• deploy/IMPROVEMENTS.md: banner marking AuthorKit findings (Added Skill for Building Blocks for EDS when AEM Sites Universal Editor is your Content Source #4/feat: add AEM workflow troubleshooting and debugging skills #21/feat: add Universal Editor component model skill #26/feat: add workflow-purge skill and fix launcher eventType bitmask #40/docs(migration): add OSGi → Cloud Manager reference and wire migration skill #81/feat: adding aem content distribution skill in AEMaaCS skills #84) as legacy; feat: adding aem content distribution skill in AEMaaCS skills #84 superseded.
• diff/scripts/diff-profiles.mjs: BLANK_RENDER hint rewritten for vanilla (the gate IS driven; blank = harness/decorate failure).
• rollout/reference/multilingual.md: language-route the header/footer blocks instead of loadStaticFragment.

Design choices worth a look

• Self-contained header/footer blocks chosen as the default (vs the boilerplate fragment-content header that loadFragment('/nav')); the fragment-content path is documented as the opt-in for when nav must be DA-authorable.
• Fonts simplified to no JS-driven font class (metric-match + font-display: swap does the CLS work); the boilerplate body.appear display gate is kept as-is.

Risk / not done here

• No actively-maintained AuthorKit site is assumed; the legacy recipe survives only as history in IMPROVEMENTS.md.
• Capability parity (lang switcher, header search, multilingual chrome) is described for vanilla but not shipped as reusable blocks in this PR — worth a follow-up if chrome-heavy migrations regress.

🤖 Generated with Claude Code

[github-actions]

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