v5.0.0

The executor's condition grammar is now a plugin registry: flags, membership ("role is one of admin, owner") and the original comparison grammar ship built in, and a deployment can register its own grammar ahead of them. Every execution trace records which steps ran and which decision rules fired, so GET /instruction-sets/{id}/coverage can say exactly which steps and rules the test cases never reach, and each test run stores its coverage summary.

GET /ops/overview pulls it together: sets by state, coverage of the latest runs with the weakest sets listed, open drift flags, review SLAs and publish statistics, plus the plugin list. The README gains a Releases table summarising v1 through v5. Migration 0005 adds test_runs.coverage. 48 tests.