v2.9.34

v2.9.34 — audit-ledger closure wave

Closes 4 of 7 carryover items from AUDIT_LEDGER_v2.9.34.md plus HS3
(missing CLAUDE.md operating contract):

- HS3 / CLAUDE.md operating contract (repo root)
- #9 / alert investigation (23 alerts triaged)
- #10 / 1k DAG fixture with branching/merging
- #16 / cryptographic signoff stub + schema v2 wire format
- #17 / SOP checklist schema + validator

Partial close — #6 P6 expected-value (engineering scaffolding only;
P6-values portion stays user-blocked).

Engine math unchanged from v2.9.33; crossval 747/747 holds.

See CHANGELOG.md v2.9.34 entry for the full breakdown.