Test coverage: 80.8% to 85% #300

Total statement coverage is 80.8% (go test ./... -covermode=atomic, 2026-11-12): 19,170 statements, about 3,700 uncovered. That is roughly 130 statements above 80%. #298 puts a 78% floor in CI.

Reaching 85% needs about 255 more covered statements. The cheapest places to find them:

• blast_radius.go
• collide.go
• cmd/drift.go
• raise min= in .github/workflows/ci.yml to 83 once total passes 85%

Next after that, toward 90% (about 735 statements from today): cmd/hooks.go (260 uncovered) and cmd/doctor.go (183).

Hard to unit test, and not excluded from the total: main.go (368), mcp/main.go (165), cmd/setup.go and cmd/plugin.go (144 each), cmd/serve.go (72).