chore(ackit): v0.5.1 public surface parity (TASK-0089)

[Cynrath]

Summary

Hosted-docs/root-UI correction for ACKit v0.5.1. No redesign, no new
product release, no Browser Companion.

• Fixes the docs generator at its source
  (scripts/sync-ackit-docs.mjs), not hand-edited HTML: version stays
  dynamic, safety contract preserved (docs sandbox, root index
  protected, theme assets hand-maintained, no network/exec/telemetry).
• New generated pages + nav: Status, Provider Surfaces, Trust Flow
  (30 pages total, nav 30 targets).
• Updated generated content: Overview (v0.5 capability set), CLI
  (status, checkpoint import, verification --bundle),
  Verification (bundle v2, state binding, stored verdict v2, legacy
  v1, independence, replay, staleness), Checkpoints (handoff v2,
  import, status snapshot, redaction, refusal codes), Security (v0.5
  containment delta), MCP (16 tools incl ackit_status), SDK
  (status parity), VS Code (status-integrated Tasks view).
• llms.txt / llms-full.txt regenerated with the new surfaces.
• Root index.html (hand-maintained, outside generator sandbox):
  0.4.1 to 0.5.1 on all current surfaces (JSON-LD, hero terminal,
  featured card, install snippets, docs snippet, footer), feature
  cards updated to the v0.5 trust chain plus a Trust Flow Demo card;
  design/layout/animations preserved.
• Extends scripts/verify-site.mjs (still zero-dependency) with
  dynamic root/generated version parity and hosted v0.5 marker
  guards so this drift cannot recur.

Evidence

• Generator run 1: expected pages change; run 2: zero diff
  (idempotent, hash-proven across runs).
• Theme asset hashes preserved:
  • ackit-docs.css: 8208833BEF6EEA9FD33B7A919696B93D9A39B4C92FA0F4FB2446C7D6732958C9
  • ackit-docs.js: 71B53A7FF3E85C9FD217A70955DE6DC039B3F06ABABDCDC9256DA39C805DA04163
• node scripts/verify-site.mjs: PASS (30 pages, version 0.5.1,
  nav 30 targets).
• Rendered HTML inspected: new pages carry correct titles, canonical
  URLs, active nav states, and sitemap entries.
• No generated churn outside expected ACKit docs + sitemap/robots;
  root changes limited to index.html version/feature messaging.

Scope guard

• No redesign; no theme/layout changes.
• Generator safety contract unchanged (verified by verify-site.mjs).
• Root index.html remains outside the generator sandbox.
• No Browser Companion.