Vendored floor snapshot re-synced from pi-extensions 98eb07b, which documents
the mechanism behind fork boundary violations (full parent-transcript
inheritance via index.ts:47) plus the corrected claims about tool restriction
and narrative invention. CI resolves PI_EXTENSIONS_REF from main HEAD, so a
normal build ships the package-owned copy; this keeps the committed floor
identical so scripts/smoke-test.sh's cmp assertion holds either way.
joakimp
fa04d2083d