# Architecture Compliance Baseline

> **Purpose.** Single canonical document against which every cumulative-review
> report (per `.cursor/skills/code-review/SKILL.md` Phase 7 + the implement
> skill's Step 14.5 cumulative review) computes its `## Baseline Delta` —
> the count of **carried-over**, **resolved**, and **newly-introduced**
> architecture violations. Without this file, cumulative reviews log
> "baseline not found → no Baseline Delta section emitted" and structural
> regressions are visible only pairwise per batch instead of cumulatively.

**Baseline established**: 2026-05-26 (cycle-4 Step 10, batch 1, AZ-899)
**Source-of-truth snapshot**: `_docs/06_metrics/structure_2026-05-20.md`
**Initial violation count**: **0**
**Cycle of last refresh**: 4

## Source

The "0 violations" claim is grounded in the structural facts captured by the
cycle-1-close snapshot (`_docs/06_metrics/structure_2026-05-20.md`):

| Fact | Value |
|------|-------|
| Inventory entries | 15 (14 production components C1–C13 + 1 cross-cutting `helpers/runtime_root` row) |
| Import cycles in component graph | 0 (verified across batches 88–92 cumulative reviews; no back-edges) |
| Contract files | 5 (`fdr_record_schema.md`, `fdr_client_protocol.md`, `log_record_schema.md`, the `shared_satellite_provider_ingest/` placeholder, `shared_flights_api/`) |
| `_STRATEGY_REGISTRY` composition seam | `runtime_root.airborne_bootstrap` + `runtime_root.operator_bootstrap` (single composition root per binary, ADR-009) |
| Layering rule | Layer-3 → Layer-4 imports **BANNED**; AZ-507 cross-component contract surface enforced by `tests/unit/test_az270_compose_root.test_ac6_only_compose_root_imports_concrete_strategies` lint |

The architecture is documented in `_docs/02_document/architecture.md` (ADR-001
monolith, ADR-002 build-time exclusion, ADR-009 interface-first DI,
ADR-011 single-image live+replay). File ownership is documented in
`_docs/02_document/module-layout.md`.

## Violations

*None at baseline.*

This section is the append target for every cumulative-review run that
detects an architecture finding (severity ≥ Medium, category =
`Architecture`). The append schema is documented under § Update Protocol
below.

## Update Protocol

### When a cumulative review finds a NEW architecture violation

The reviewing skill (typically `.cursor/skills/code-review/SKILL.md` Phase 7,
invoked from the implement skill's Step 14.5 cumulative review at every K=3
batches) MUST append a row to § Violations using this schema:

| Field | Example |
|-------|---------|
| Finding ID | `arch-2026-06-15-1` (date + sequence within the day) |
| Batch range | `batches 17–19 cycle 4` |
| Severity | `High` / `Medium` (Critical findings escalate immediately; Low findings stay in the per-batch report) |
| Subcategory | `import-cycle` / `cross-component-import` / `parallel-pipeline` / `layer-violation` / `seam-bypass` |
| File:line | `src/gps_denied_onboard/components/c2_vpr/ultra_vpr.py:117` |
| One-line summary | `c2_vpr imports c6_tile_cache directly, bypassing the consumer-side Protocol cut required by AZ-507` |
| Cumulative-review report | `_docs/03_implementation/cumulative_review_batches_17-19_cycle4_report.md` |
| Status | `OPEN` (newly introduced) |

The append happens IN THIS FILE, not in the cumulative-review report. The
cumulative-review report references this file's row by Finding ID.

### When a violation is resolved

Update the violating row in place: change `Status: OPEN` to
`Status: RESOLVED in batch <N> cycle <M> via <commit-hash>`. Do NOT delete
the row — the audit trail must show both the introduction and the
resolution.

### When the structural snapshot is refreshed

Any cycle that materially changes structure — new component, new
cross-component edge, new contract file, new composition root — re-snapshots
to a fresh `_docs/06_metrics/structure_<YYYY-MM-DD>.md` (the cycle-end
retrospective triggers this when the diff is non-trivial). When that
happens:

1. Update the `**Source-of-truth snapshot**` header pointer at the top of
   this file to the new file.
2. Update the `Cycle of last refresh` header to the cycle that produced the
   new snapshot.
3. Update the § Source table values (component count, cycle count, contract
   count) to match the new snapshot.
4. Do NOT clear § Violations — open findings carry across snapshots.
   Resolution status is per-finding, not per-snapshot.

The refresh script is the same one that produced `structure_2026-05-20.md`
(approach: count `src/gps_denied_onboard/components/*/` directories +
`src/gps_denied_onboard/runtime_root/` + `helpers/`; run the AZ-270
composition-root lint to detect cycles; enumerate
`_docs/02_document/contracts/` subdirectories). If the script has been
extracted into `tools/structure_snapshot.py` between cycles, use it;
otherwise the manual approach is documented at the top of the source
snapshot file.

## Baseline Delta — how cumulative-review reports consume this file

Every cumulative-review report MUST emit a `## Baseline Delta` section with
three counts derived from this file:

- **Carried-over**: count of rows whose `Status: OPEN` (or
  `Status: ACCEPTED-RISK`) was unchanged at the start of this review's
  batch window.
- **Resolved**: count of rows that transitioned from `OPEN` to
  `RESOLVED in batch ...` during this review's batch window.
- **Newly-introduced**: count of rows added during this review's batch
  window.

An empty Baseline Delta (`0 new, 0 resolved, 0 carried-over`) is still
emitted — its presence confirms the cumulative-review consulted the
baseline rather than silently skipping the section as in cycles 1–3.

## References

- Cycle-3 retro § Top 3 Improvement Actions #3 — `_docs/06_metrics/retro_2026-05-26.md`
- Cycle-1 retro § Top 3 Improvement Actions #3 (original) — `_docs/06_metrics/retro_2026-05-20.md`
- Source snapshot — `_docs/06_metrics/structure_2026-05-20.md`
- Existing-code flow Step 2 — `.cursor/skills/autodev/flows/existing-code.md` § "Step 2 — Architecture Baseline Scan"
- Implement skill Step 14.5 — `.cursor/skills/implement/SKILL.md` § "Cumulative Code Review (every K batches)"
- Architecture doc — `_docs/02_document/architecture.md`
- Module-layout — `_docs/02_document/module-layout.md`