fix: persist serialized webhook consumer lifecycle

[09473ZH]

Serialized event senders currently cannot distinguish a running consumer from a consumer that ended without business ACK. Lost responses and restarts can consequently restart work or leave the sender polling the wrong state.

Persist admission by route and stable delivery identity before starting work. Authenticated batch status/cancel requests share route authentication and bypass model admission quota. Receiver restart exposes interrupted work; the sender owns explicit recovery for serialized event routes. Cancellation persists a tombstone before stopping the consumer; consumers sharing other obligations remain running until those obligations finish or are cancelled.

Validation: canonical scripts/run_tests.sh -j 1 passed 80 tests across seven webhook/restart test files. Real HTTP replay covers lost responses, repeated admission, busy scopes, normal completion, active cancellation, late delivery and durable restart. The additional shared-consumer cancellation check also passes. New files pass Ruff; changed modules compile. This fork has no pre-commit configuration.

Dependency for CorgiCortex/Qortex-Trading-Harness#285. completed means the consumer ended, not that business ACK or trading execution completed. Production deployment remains paused pending the Harness integration and separate hardware validation.

[09473ZH]

Harness integration: https://github.com/CorgiCortex/Qortex-Trading-Harness/pull/286 pins this PR's 2b4dc8369fc57f58967c4888f2d80a8fa63217ff and installs the lifecycle ledger module in the source overlay. Production remains paused; merge/deployment and hardware acceptance are separate.