release: bring final 2.0.0 performance corrections from dev to main

[SunSi12138]

Bring the final reviewed runtime performance corrections for SharpLink 2.0.0 from dev into main before publishing the release from main.

The release branch merges current main history into dev commit bae9e50844fc45b1aaf94de676cd73e86654f424 to satisfy main’s strict up-to-date check. Its tree is identical to that verified dev commit (af745f3efadd4cc519cd7e9f8d0fdf3be827f934); the merge adds no source changes. This replaces the direct-dev draft #679, whose head lacked main’s merge history.

• perf(runtime): reduce timed RPC emission overhead and restore batching #677 removes unnecessary timed-call emission overhead and allows ready timed requests to share a publication boundary while preserving deadline arbitration and frame ownership.
• perf(server): avoid stream callback allocation for calls without input streams #678 avoids allocating input-stream callback state for calls that have no input streams. The measured OneWay allocation falls by 64 B/message with unchanged throughput; streaming behavior is unchanged.

The latest source state passed a full non-incremental Release solution build (0 warnings/errors), 1825 unit tests and 451 integration tests, with no failures or skips. Both source PRs passed their GitHub checks and include focused tests and before/after BenchmarkDotNet evidence.

Release status: this PR remains a draft while the final hardware performance assessment is incomplete. Baremetal TCP delivery stalls are sensitive to unrelated traffic on its network interface; the requested temporary EEE diagnostic requires an administrator action on that machine. A fresh OneWay ABA completed without errors but its two 1.1.1 baselines drifted by 14.8%, so that run cannot establish a reliable pass/fail comparison.

After the hardware issue is resolved, merge into main, run the exact-main release gate and final 1.1.1 → 2.0.0 → 1.1.1 comparison using the verified main packages. Launch a fresh five-hour GitHub Actions soak for that main commit and continue release work while it runs, as authorized. Do not tag or publish packages until the remaining release validation is complete.