atelier/matrix/domain-coverage.md

# Domain Coverage

> Where each core principle applies across the domains. The complement to `principles-matrix.md`: the matrix maps domain → core; this maps core → domains.

## Core Principle Coverage

| Core Principle | Domains that derive from it | Count |
|----------------|---------------------------|-------|
| C1 Correctness | All 17 (v0.1: 11; v0.2: infrastructure-as-code, kubernetes; v0.3: gitops-operators, ai-ml, i18n, compliance) | Universal |
| C2 Clarity | v0.1: uiux, api, data, testing, observability, errors, documentation, devops; v0.2: infrastructure-as-code, kubernetes; v0.3: gitops-operators, ai-ml, i18n, compliance | 14 |
| C3 Simplicity | v0.1: security, data, testing, performance, documentation, concurrency, devops; v0.2: infrastructure-as-code; v0.3: gitops-operators, i18n, compliance | 11 |
| C4 Locality | v0.1: testing, concurrency; v0.2: infrastructure-as-code, kubernetes; v0.3: gitops-operators, i18n | 6 |
| C5 Reversibility | v0.1: api, data, uiux, concurrency, devops; v0.2: infrastructure-as-code, kubernetes; v0.3: gitops-operators, ai-ml, i18n, compliance | 11 |
| C6 Composability | v0.1: api, security, observability, errors, documentation, concurrency; v0.2: infrastructure-as-code, kubernetes; v0.3: gitops-operators, ai-ml, i18n, compliance | 12 |
| C7 Observability | v0.1: api, data, testing, performance, observability, errors, devops; v0.2: infrastructure-as-code, kubernetes; v0.3: gitops-operators, ai-ml, i18n, compliance | 13 |
| C8 Economy | v0.1: security, testing, performance, observability, concurrency; v0.2: kubernetes; v0.3: gitops-operators, i18n, compliance | 9 |

## Interpretation

- **C1 Correctness** is universal — every domain derives from it. This confirms C1 as the floor.
- **C4 Locality** is the narrowest (2 domains: testing independence, concurrency boundaries). Locality is inherently domain-specific; not a gap.
- **C2 Clarity** and **C7 Observability** are the next-most-derived, confirming they are cross-cutting concerns.
- **C6 Composability** appears in 6 domains — it is most relevant where parts combine (api, errors, observability, documentation, concurrency) and least relevant where the unit is monolithic.

## Per-Domain Coverage

| Domain | C-rules derived from | Notes |
|--------|---------------------|-------|
| UI/UX | C1, C2, C3, C5, C7 | User-facing; clarity + reversibility |
| API | C1, C2, C3, C5, C6, C7 | Contracts; composability + stability |
| Security | C1, C3, C6, C7, C8 | 8/10 non-tradeable (promoted to C1) |
| Data | C1, C2, C3, C5, C7 | Truth + migration safety |
| Testing | C1, C2, C3, C4, C7, C8 | Independence (C4) is unique |
| Performance | C1, C3, C6, C7, C8 | Economy + measurement |
| Observability | C1, C2, C6, C7, C8 | Self-referential (P7 derives from C7) |
| Errors | C1, C2, C5, C6, C7 | Errors as data + reversibility |
| Documentation | C1, C2, C3, C5, C6, C8 | Docs-as-code + living docs; economy of process (P1) |
| Concurrency | C1, C3, C4, C5, C6, C7, C8 | Broadest derivation; locality (C4) unique |
| DevOps | C1, C2, C3, C5, C7, C8 | Reproducibility + rollback; economy of effort (P2) |
| Infrastructure as Code | C1, C2, C3, C4, C5, C6, C7 | Declarative + state + composition; broadest derivation alongside Concurrency |
| Kubernetes | C1, C2, C4, C5, C6, C7, C8 | Declarative + reversibility + economy; broad derivation (7 C-rules) |
| GitOps + Operators | C1, C2, C3, C4, C5, C6, C7, C8 | Source-of-truth + reconciliation + pull-locality + least privilege; broadest derivation (8 C-rules, tied with i18n) |
| AI / ML | C1, C2, C5, C6, C7 | Reproducibility + lineage + serving observability |
| i18n | C1, C2, C3, C4, C5, C6, C7, C8 | Locale + formatting + direction + reversibility; broadest derivation (8 C-rules) |
| Compliance | C1, C2, C3, C5, C6, C7, C8 | Audit + policy-as-code + retention + posture |

## v0.2 Domain Coverage (per IDEATE-03 schema)

| Domain | P-count | Derived-doc-count | Manifest-listed | Status |
|--------|---------|-------------------|-----------------|--------|
| Infrastructure as Code | 10 | 4 (terraform, opentofu, state, modules) | ✓ | complete |
| Kubernetes | 10 | 6 (workloads, networking, storage, rbac, helm, kustomize) | ✓ | complete |

## v0.3 Domain Coverage (per IDEATE-03 schema)

| Domain | P-count | Derived-doc-count | Manifest-listed | Status |
|--------|---------|-------------------|-----------------|--------|
| GitOps + Operators | 10 | 4 (argocd, flux, operators, progressive-delivery) | ✓ | complete |
| AI / ML | 10 | 4 (data-versioning, model-evaluation, serving, monitoring-drift) | ✓ | complete |
| i18n | 10 | 4 (locale-resources, formatting, rtl-bidi, testing-i18n) | ✓ | complete |
| Compliance | 10 | 4 (audit-logs, data-retention, policy-as-code, evidence) | ✓ | complete |

## Gaps and Notes

- No domain derives from only one C-rule. The minimum is 4 (UI/UX: C1, C2, C3, C5, C7 — actually 5). Every domain is multi-rooted.
- **Concurrency**, **Infrastructure as Code**, and **Kubernetes** are tied for the broadest derivation among v0.1/v0.2 platform domains (7 C-rules each) — these domains touch the most core concerns.
- **GitOps + Operators** and **i18n** are tied for the single broadest-derivation domain overall (8 C-rules each: C1–C8). GitOps adds C4 (pull-credential locality) alongside its source-of-truth/reconciliation/least-privilege derivation; i18n touches correctness, clarity, simplicity, locality, reversibility, composability, observability, and economy (expansion accommodation). This is consistent with both domains' cross-cutting nature.
- **UI/UX** and **API** are the most user-facing; they emphasize C2 (Clarity) heavily.
- **Security** is the only domain with explicit non-tradeable declarations; this promotes 8 of its rules to C1-equivalent per `core/conflict-resolution.md` §6.
- **v0.2 expansion:** C4 (Locality) grew from 2 to 4 domains (added infrastructure-as-code state locality, kubernetes namespace blast-radius). C6 (Composability) grew from 6 to 8. The two new domains are broad-derivation domains (7 C-rules each), consistent with Concurrency's breadth.
- **v0.3 expansion:** C3 (Simplicity) grew from 7 to 11 (added gitops-operators declarative simplicity, i18n flexible layout, compliance structural redaction). C4 (Locality) grew from 4 to 6 (added gitops-operators pull-credential locality, i18n resource/text-direction locality). C5 (Reversibility) grew from 7 to 11 (added all four v0.3 domains — gitops history, ai-ml reproducibility, i18n translation versioning, compliance append-only/retention). C6 (Composability) grew from 8 to 12. C7 (Observability) grew from 9 to 13 (added all four v0.3 domains — reconciliation, drift detection, format correctness, posture). C2 (Clarity) grew from 10 to 14. The v0.3 expansion broadens every non-universal C-rule's coverage, confirming the four new domains are cross-cutting and well-rooted.