Adds the cycle-4 product implementation completeness gate report
(verdict: PASS) and the final implementation report for the .NET 10
migration. Records the Step 16 handoff to Step 11 (test-run skill)
to avoid duplicating the full-suite run already executed during
AC-6 verification (271/271 unit + full integration suite green).
Co-authored-by: Cursor <cursoragent@cursor.com>
Oleksandr Bezdieniezhnykh