Codexicon v2.8.1

2.8.1 — Efficient diagnostics and verification output

• Classified exact read-only Codexicon manager plans and diagnostics without allowing apply mutations or abbreviated apply flags through the verification gate.
• Reduced successful canonical test output while preserving complete failure diagnostics.
• Returned subagent concurrency to user and runtime policy and added validation against reintroducing a project-level fixed cap.
• Made Git-heavy test-fixture cleanup clear read-only artifacts, retry, and fail visibly instead of silently accumulating workspace state on Windows.