First release prepared for OSPO submission. Multi-targets net8.0 and net10.0 with
opt-in net11.0, carries a defect ledger in docs/known-issues.md recording what was
found and what remains, and ships with CI green on Linux and Windows.

Includes the fix for the Linux-only crash in which code-coverage instrumentation
segfaulted the Roslyn-heavy generator test host.