chameleon 3.3.0

Changed

• The Stop pipeline now lives in chameleon_mcp/stop/ (advisories, gates,
  pipeline with per-root RootContext); hook_helper keeps the same entry point
  and seams. Behavior-preserving: no output or decision changes.
• Archetype renames now rewrite the idiom store, so renamed archetypes keep
  scoping idioms and survive view regeneration.
• A v3 teammate's deprecation made via idioms.md is folded into the store
  (reactivation via the view stays refused; use /chameleon-teach).
• Idiom store records are read through the hardened profile-artifact path
  (symlink-refusing, size-capped).
• Teach and trust envelopes report idioms_migrated / idioms_quarantined
  when their call triggered the one-time store migration.

Removed

• The dead legacy idiom markdown writers (_transition_slug_to_deprecated,
  _write_new_deprecated_idiom, _find_all_slug_sections,
  _render_idiom_block); the store owns all idiom writes.