Adapt FalconOrtiz's owner-mailbox proposal from #101564 onto the current
notification poller and topical modules. The durable mailbox is cross-process
ingress only: the existing owner admits its normal prompt turn after the
current turn and human FIFO clear. Retain immutable receipts, stable admission
identities, capability and lease fencing, compression lineage, and disable
blind recovery replay of imported turns.
The original stale server hunks and expiring receipt protocol were rebuilt
rather than cherry-picked: the current facade decomposition and durable busy
admission contract differ. Credit the earlier owner-mailbox work in #100544
and durable producer work in #100319.
Co-authored-by: fangliquanflq <fangliquan@qq.com>
Co-authored-by: 686f6c61 <github@00b.tech>
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