Coverage policy

The aggregate test gate requires at least 80% branch-aware coverage. The following high-risk modules also have explicit floors because regressions in these paths affect filesystem safety, lifecycle attachment, or machine-facing contracts:

Module	Floor
base_cli._attach	75%
base_cli._click_compat	80%
base_cli._private_files	75%
base_cli._runtime	80%
base_cli.command_protocol	85%
base_cli.history	75%
base_cli.redaction	90%

CI writes a branch-aware coverage.json report and runs scripts/validate_coverage.py against these floors. A floor change belongs in the same pull request as the tests that justify it. Platform-specific tests must cover both the native path and the safe fallback where the operating system provides a different filesystem primitive.