The previous ENV regex `/[\\/]\.env\.[a-z]+$/` only matched a single
lowercase segment after `.env`. Multi-segment and mixed-case variants
such as `.env.production.local.backup`, `.env.stage-1.local`, and
`.env.CI.secret` slipped past the hook. Replaced with
`/[\\/]\.env(\.[A-Za-z0-9._-]+)*$/` which matches `.env` plus any
number of dot-separated alphanumeric/dot/hyphen/underscore segments.
`.envrc` (direnv config, no dot separator) is still allowed.
Addresses critical review 2026-04-20 §2 B1 (HIGH).
Tests: 7 added (6 new multi-segment BLOCK cases + 1 .envrc ALLOW).
All 1494 tests pass.
New policy-loader.mjs reads .llm-security/policy.json with deep-merge against
defaults that exactly match existing hardcoded values. Integrated into all 7 hooks:
- pre-prompt-inject-scan: injection.mode (env var still takes precedence)
- post-session-guard: trifecta.mode, window_size, long_horizon_window
- pre-edit-secrets: secrets.additional_patterns
- pre-bash-destructive: destructive.additional_blocked
- pre-write-pathguard: pathguard.additional_protected
- pre-install-supply-chain: supply_chain.additional_blocked_packages
- post-mcp-verify: mcp.volume_threshold_bytes, mcp.trusted_servers
Backward compatible: no policy file = identical behavior to v5.1.0.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
