{
 "id": "tier2_leak_prevention_20260620",
 "title": "Tier 2 Sandbox File Leak Prevention (revert + 3-layer defense)",
 "type": "fix",
 "status": "shipped",
 "priority": "A",
 "created": "2026-06-20",
 "shipped": "2026-06-20",
 "owner": "tier2-tech-lead",
 "spec": "conductor/tracks/tier2_leak_prevention_20260620/spec.md",
 "plan": "conductor/tracks/tier2_leak_prevention_20260620/plan.md",
 "scope": {
 "new_files": 5,
 "modified_files": 1,
 "deleted_files": 0
 },
 "depends_on": [],
 "blocks": [],
 "test_summary": {
 "default_on_tests": 25,
 "opt_in_tests_sandbox": 0,
 "opt_in_tests_smoke": 0
 },
 "verification_criteria": [
 "The 4 tier-2 sandbox-only files from commit 00e5a3f2 are removed/reverted from master (fab2e55b)",
 "scripts/audit_tier2_leaks.py exits 0 on a clean main repo working tree",
 "scripts/audit_tier2_leaks.py --strict exits 1 when a forbidden file is present",
 "conductor/tier2/githooks/pre-commit exists, is shell-executable, and reads from forbidden-files.txt",
 "Pre-commit hook auto-unstages staged forbidden files (verified by tests/test_tier2_pre_commit_hook.py)",
 "scripts/tier2/setup_tier2_clone.ps1 installs the pre-commit hook into the clone (.git/hooks/pre-commit)",
 "All 13 audit tests + 12 hook tests + 21 existing tier-2 tests pass"
 ],
 "risk_register": [
 {
 "id": "R1",
 "title": "Pre-commit hook uses CRLF-stripping that may not handle all line endings",
 "likelihood": "low",
 "scope_impact": "minimal; hook is best-effort, fails open",
 "mitigation": "Tests cover both CRLF and LF configs (test_hook_uses_config_from_project_root writes via Python text mode which produces CRLF on Windows; the test_hook_unstages_modified_opencode_json test covers a real-world config file with CRLF endings)"
 },
 {
 "id": "R2",
 "title": "git rm --cached --quiet may exit non-zero on edge cases (staged content diverges from both HEAD and working tree)",
 "likelihood": "medium",
 "scope_impact": "minimal",
 "mitigation": "Hook uses --force flag (required when index content differs from HEAD and working tree). Discovered during TDD; documented in hook source."
 },
 {
 "id": "R3",
 "title": "Tier-2 branches (tier2/result_migration_app_controller_phase6_20260619, tier2/test_sandbox_hardening_20260619) still contain the offender commit 00e5a3f2",
 "likelihood": "high",
 "scope_impact": "the implementation may be larger than the spec suggests if those branches need rebase before next merge",
 "mitigation": "Documented in TRACK_COMPLETION §Next Steps. User must rebase these branches on the new master tip (8f54deda) before merging. No automation; explicit user action required because force-push is required."
 },
 {
 "id": "R4",
 "title": "Forbidden patterns are substring matches; a future legitimate file path containing 'opencode.json' or 'mcp_paths.toml' as substring would be falsely flagged",
 "likelihood": "low",
 "scope_impact": "minimal",
 "mitigation": "Patterns are in a config file at conductor/tier2/githooks/forbidden-files.txt; edit + reinstall if a future false positive is discovered. The pre-commit hook + audit script are independent and easy to update."
 },
 {
 "id": "R5",
 "title": "Pre-commit hook must exit 0 (not block tier-2 mid-flow); tier-2 might miss the warning if stderr is not surfaced",
 "likelihood": "medium",
 "scope_impact": "minimal",
 "mitigation": "Hook writes clear warning to stderr (visible in git commit output). Tier-2 failcount machinery in scripts/tier2/failcount.py does not count hook fires as failures. If tier-2 misses the warning, the audit script catches the leak at the working-tree level."
 }
 ],
 "architecture_reference": {
 "primary_styleguide": "conductor/code_styleguides/feature_flags.md (file-presence = enabled; the hook is enabled iff the script + config are present in the clone)",
 "secondary_styleguides": [
 "conductor/code_styleguides/workspace_paths.md (audit script uses SKIP_DIRS convention)"
 ],
 "related_tracks": [
 "conductor/archive/tier2_autonomous_sandbox_20260616/",
 "conductor/tracks/test_sandbox_hardening_20260619/"
 ],
 "pattern_references": [
 "conductor/tier2/githooks/pre-push (existing hook pattern, copy template for the new pre-commit hook)",
 "scripts/audit_exception_handling.py (audit script pattern, copy for audit_tier2_leaks.py)"
 ]
 },
 "deferred_to_followup_tracks": [
 {
 "title": "CI integration of audit_tier2_leaks.py --strict",
 "description": "Wire scripts/audit_tier2_leaks.py --strict into the existing 11-tier CI pipeline (or a dedicated pre-commit CI job) so the audit runs on every PR. The script exists; only the wiring is missing.",
 "track_status": "not yet specced"
 },
 {
 "title": "Rebase of stale tier-2 branches on the post-revert master",
 "description": "tier2/result_migration_app_controller_phase6_20260619 and tier2/test_sandbox_hardening_20260619 both contain the offender commit 00e5a3f2. When those branches are next merged to master, the merge will conflict with fab2e55b. User should rebase on origin/master@8f54deda.",
 "track_status": "user action required"
 }
 ],
 "regressions_and_pre_existing_failures": [],
 "pre_existing_failures_remaining": [],
 "user_directives": [
 "Tier-2 autonomous must NEVER commit those files again",
 "Use a pre-commit hook (NOT gitignore) for the enforcement",
 "Selective revert: only the user-named files (./opencode/*, mcp_paths.toml, opencode.json); leave other 00e5a3f2 changes alone",
 "Recovery from data loss: do not use git restore or git reset without explicit permission"
 ]
}