---
session_id: S-2026-0221-1539
timestamp: 2026-02-21T14:39:15Z
predecessor: S-2026-0221-1426
tasks_active: [T-200, T-220, T-227, T-230]
tasks_touched: [T-230, T-227, T-220, T-229, T-231, T-228]
tasks_completed: []
uncommitted_changes: 147
owner: claude-code
session_narrative: ""
---

# Session Handover: S-2026-0221-1539

## Where We Are

Completed a full enforcement hardening cycle: T-228 (inception) identified 13 bypass vectors across 3 enforcement layers, T-229 fixed the 2 HIGH severity issues (--no-verify Tier 0 block + settings.json protection + 6 new destructive patterns), T-230 added integrity checks (enforcement baseline, matcher coverage, NotebookEdit support), T-231 updated git hook messaging and registered remaining gaps. 84/84 unit tests pass. New `fw enforcement {baseline|status}` command available.

## Work in Progress

<!-- horizon: now -->

### T-200: "Discovery layer design — pattern detection, omission finding, insight surfacing (T-194 Phase 4)"
- **Status:** captured (horizon: now)
- **Last action:** Untouched this session
- **Next step:** Begin inception exploration
- **Blockers:** None
- **Insight:** None

### T-220: "Fabric component detail — inline source code viewer"
- **Status:** started-work (horizon: now)
- **Last action:** Source viewer implemented (7ed0b1d) in prior session
- **Next step:** Human ACs pending (dark theme contrast, collapsible section UX)
- **Blockers:** Waiting for human verification
- **Insight:** None

### T-227: "Fix fabric page — subsystem cards link to themselves, dropdown filters broken"
- **Status:** work-completed (horizon: now)
- **Last action:** Fixed prior session (7f5fbf3). Human AC pending (filtered view visual quality)
- **Next step:** Human sign-off on filtered view
- **Blockers:** None
- **Insight:** None

### T-230: "Fix MEDIUM severity enforcement bypasses — B-009, B-012, integrity checks"
- **Status:** work-completed (horizon: now)
- **Last action:** All agent ACs done. Human AC pending: review whether to add NotebookEdit to settings.json PreToolUse matcher
- **Next step:** Human updates settings.json: change `Write|Edit` to `Write|Edit|NotebookEdit` in check-active-task.sh entry
- **Blockers:** None
- **Insight:** settings.json is now protected by B-005 — human must edit it manually

## Inception Phases

**1 inception task(s) pending decision** — run `fw inception status` for details.

## Gaps Register

**3 spec-reality gap(s) being watched** — see `.context/project/gaps.yaml`

- **G-004** [low]: Multi-agent collaboration untested
- **G-011** [low]: PostToolUse hooks are advisory-only — cannot block actions
- **G-012** [low]: NotebookEdit and other side-effect tools not covered by PreToolUse task gate

Run `fw audit` to check if any trigger conditions are met.

## Decisions Made This Session

1. **Anchor `--no-verify` pattern to git context (`\bgit\b[^;|&]*--no-verify\b`)**
   - Why: Bare `--no-verify` matched in echo strings and comments (false positive caught during testing)
   - Alternatives rejected: Broad `--no-verify\b` pattern (too many false positives)

2. **Block settings.json writes in check-active-task.sh rather than check-tier0.sh**
   - Why: The task gate runs on Write|Edit and can distinguish file paths; Tier 0 only sees Bash commands
   - Alternatives rejected: Adding to check-tier0.sh (wrong hook — Tier 0 gates Bash, not Write/Edit)

3. **Store enforcement baseline as SHA256 of JSON-serialized hooks (sorted keys)**
   - Why: Deterministic hash that's immune to whitespace/formatting changes
   - Alternatives rejected: Full file hash (too brittle — any settings.json change triggers alarm)

## Things Tried That Failed

1. **Verification commands piping to `grep -q`** — SIGPIPE (exit 141) when grep closes pipe early. Same issue as T-227. Fixed by checking exit code directly (`test $? -eq 2`).
2. **Using `local` in fw case block** — `local` only works inside bash functions, not in main script case blocks. Fixed by using global variables with `EF_` prefix.
3. **`fw doctor` grep on colored output** — `grep -qv "failure"` matched "no failures" text, causing false failure. Fixed by checking `fw doctor` exit code instead.

## Open Questions / Blockers

1. Human should review T-230 AC: add NotebookEdit to settings.json PreToolUse matcher?

## Gotchas / Warnings for Next Session

- `fw enforcement baseline` must be re-run if settings.json hooks are changed (otherwise `fw doctor` will report baseline mismatch)
- Hooks snapshot at session start — settings.json edits need a session restart to take effect
- Verification pipe SIGPIPE: always use `cmd > file && grep file` or `cmd; test $? -eq N` — never `cmd | grep -q`

## Suggested First Action

Check human ACs for T-220 (source viewer dark theme/collapsible UX) and T-227 (filtered view quality), or begin T-200 (discovery layer inception).

## Files Changed This Session

- Created: `docs/reports/T-228-enforcement-bypass-analysis.md`, `.context/project/enforcement-baseline.sha256`
- Modified: `agents/context/check-tier0.sh` (B-001 + B-003 patterns), `agents/context/check-active-task.sh` (B-005 + notebook_path), `bin/fw` (enforcement subcommand + doctor checks), `agents/git/lib/hooks.sh` (bypass messages), `.git/hooks/commit-msg`, `.git/hooks/pre-push`, `.context/project/gaps.yaml` (G-011, G-012)

## Recent Commits

- 97062d6 T-231: Update hook bypass messages to reference Tier 0 approval, register enforcement gaps
- dc8ba82 T-230: Update enforcement analysis report with fixes applied
- 553b6dc T-230: Fix verification command — use exit code instead of grep on colored output
- 3c87b21 T-230: Add enforcement integrity checks — matcher coverage, baseline hash, NotebookEdit support
- fa105f4 T-229: Fix verification commands — avoid SIGPIPE by checking exit code directly

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## Handover Quality Feedback (for next session to complete)

- Did this handover help? [ ]
- What was missing?
- What was unnecessary?
