[0.3.0-C] Revalidation, provenance, sign-off, rollback, and cross-surface parity

[mberrys]

Revalidate published bytes, one provenance chain, identity-bound sign-off, forward-only rollback, same semantics on desktop/CLI/PageMaster/Action Lists.

Depends on #266 and #369. Related: #267, #129, #237, #32, #133, #44, #134.