5.8.6

Maintenance release: build-warning cleanup, no behaviour change.

Changed

• Cleared five Swift 6 SendableClosureCaptures warnings in the AVIO size-probe. The staggered-concurrent open-time size probe (the #107 follow-up that parallelised the open-time size ladder) kept its resolvedSize / outstanding counters as mutable locals and passed each probe as a plain () -> Int64 thunk, so Swift 6's strict concurrency checker flagged the DispatchQueue.asyncAfter @Sendable closures that captured them. The synchronisation was already correct: every read and write is guarded by a single NSCondition. The shared probe state now lives in a condition-guarded @unchecked Sendable box and the probe thunk is marked @Sendable, which expresses that invariant to the compiler. No wire or timing behaviour changes; the package now builds warning-free under Swift 6.

Surfaced while sweeping build warnings ahead of the Sodalite 1.0 release. Consumers on 5.8.5 can bump at leisure; there is no functional difference.