Release RustQueue 0.8.2

[SamuelSupe]

What

• align no-Channel retention with NSQ so acknowledged messages remain available to the first durable Channel
• reduce durable FIN/REQ commit overhead while preserving the bounded group and fsync boundary
• harden direct-Broker benchmark correctness, shutdown, warmup, and drain accounting
• prepare the 0.8.2 release metadata and documentation

Why

RustQueue previously allowed acknowledged publishes without a Channel to age past the bootstrap window before a durable Channel was created. This release promotes that boundary to a persisted durability invariant and includes the measured Channel commit-path improvements developed for 0.8.2.

Release decision

The optional 60-run OrbStack performance qualification was not run. The release makes no formal throughput claim; when a full qualification artifact is present, the metadata verifier still validates it strictly.

Checks

• OrbStack short three-scenario preflight plus three alternating raw-write A/B pairs; no delivery hard failures
• full workspace tests and Clippy
• console typecheck/build and Helm lint/template checks
• all 7 fuzz smoke targets in OrbStack using a named target volume after a host FUSE write stall
• Go/Python core and secure NSQ compatibility matrices
• release metadata verification at 0.8.2