[SunSi12138]

Current version: rebased onto latest dev after #813

Current head: 13e313ab1831
Base: 9fb2744300ee, including merged #807, #808, #809, #811, #812, and #813.

This is a clean, single commit based directly on current dev. It preserves the frozen #801 audit selection after #806 independently deleted one candidate: 44 unused non-public methods removed, with 1 bodyless source-generated logger partial intentionally retained. Scope: 31 production files, +26/-877 vs the new base. No additional candidates, public/generated ABI, or wire-contract changes are introduced by #810.

Conflict resolution and cleanup

• SharpLinkClient.RpcChannel.cs: retain refactor(3.0)!: decouple IRpcChannel from unused client-stream sink (#801) #811's deletion of the unsupported channel SendClientStreamAsync<T> facade and refactor(3.0): delete 44 remaining verified unused methods after #806 (#801) #810's deletion of the unused SendRpcCall. Do not restore either method.
• RpcSessionExtensions.cs: retain refactor(runtime): remove test-only unbounded RPC error send path (#801) #813's deletion of the test-only SendRpcErrorAsync and its private SendErrorFrame helper and refactor(3.0): delete 44 remaining verified unused methods after #806 (#801) #810's other unused send-method removals. Preserve the production SendRpcErrorWithBackpressureAsync, SendErrorFrameWithBackpressureAsync, and handshake SendErrorFrameAndFlushAsync paths.
• Remove isolated /// XML documentation lines left at deletion sites in RpcSessionExtensions.cs, StreamManager.cs, and StripedLongMap.cs.
• Verified the new PR diff against current dev contains no non-whitespace added lines; upstream deletions and unrelated merged changes remain in the base. GitHub now reports mergeable: true, 1 commit ahead / 0 behind.

CI for this exact head

• ✅ PR Fast: Release build, whitespace formatting, maintainability gate, unit, generator, load-test tests, and allocation gate.
• ✅ PR Package Smoke: Release build, trim-only smoke, Linux x64 NativeAOT smoke, packing, NuGet contract verification, and package smoke.
• ✅ CodeQL, Pending and codec validation, Extension fault containment, and Codec Padding Security Evidence.
• Additional UnsafeBlit layout and Codec Mobile evidence is tracked independently; consult run status before review.

Do not attribute historical CI to this commit. Prior rebase validation #38116153659 validated the earlier b07e85a5 head based on #806, not this replacement head.

Review: still Draft; PR Extended (full IntegrationTests, desktop compatibility and extended NativeAOT) is triggered when the PR becomes ready for review. No merge requested.

Related #801, #806, #811, #813.

[SunSi12138]

Exact-head cross-platform NativeAOT evidence

Actions #38115419654 checked out this PR's exact committed source 0b735a74e94838858cfc4349487d66fb5ab102d2 with an explicit commit-hash assertion.

• PR 810 - osx-arm64 — succeeded: full Release solution build plus actual NativeAOT TCP, shared-memory, SharpPack sidecar and PreCredit streaming publish/run; job log.
• PR 810 - win-x64 — succeeded: full Release solution build plus actual NativeAOT TCP, shared-memory, SharpPack sidecar and PreCredit streaming publish/run; job log.

No test substitution or modified checkout: workflow lives on the separate audit branch, and checks the PR's source at the pinned SHA. This is real desktop NativeAOT evidence; does not claim mobile hardware coverage.