docs(13): add validation strategy

.planning/phases/13-design-system-foundation/13-VALIDATION.md

@@ -0,0 +1,76 @@
+---
+phase: 13
+slug: design-system-foundation
+status: draft
+nyquist_compliant: false
+wave_0_complete: false
+created: 2026-05-16
+---
+
+# Phase 13 — Validation Strategy
+
+> Per-phase validation contract for feedback sampling during execution.
+
+---
+
+## Test Infrastructure
+
+| Property | Value |
+|----------|-------|
+| **Framework** | {pytest 7.x / jest 29.x / vitest / go test / other} |
+| **Config file** | {path or "none — Wave 0 installs"} |
+| **Quick run command** | `{quick command}` |
+| **Full suite command** | `{full command}` |
+| **Estimated runtime** | ~13 seconds |
+
+---
+
+## Sampling Rate
+
+- **After every task commit:** Run `{quick run command}`
+- **After every plan wave:** Run `{full suite command}`
+- **Before `/gsd-verify-work`:** Full suite must be green
+- **Max feedback latency:** 13 seconds
+
+---
+
+## Per-Task Verification Map
+
+| Task ID | Plan | Wave | Requirement | Threat Ref | Secure Behavior | Test Type | Automated Command | File Exists | Status |
+|---------|------|------|-------------|------------|-----------------|-----------|-------------------|-------------|--------|
+| 13-01-01 | 01 | 1 | REQ-{XX} | T-13-01 / — | {expected secure behavior or "N/A"} | unit | `{command}` | ✅ / ❌ W0 | ⬜ pending |
+
+*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*
+
+---
+
+## Wave 0 Requirements
+
+- [ ] `{tests/test_file.py}` — stubs for REQ-{XX}
+- [ ] `{tests/conftest.py}` — shared fixtures
+- [ ] `{framework install}` — if no framework detected
+
+*If none: "Existing infrastructure covers all phase requirements."*
+
+---
+
+## Manual-Only Verifications
+
+| Behavior | Requirement | Why Manual | Test Instructions |
+|----------|-------------|------------|-------------------|
+| {behavior} | REQ-{XX} | {reason} | {steps} |
+
+*If none: "All phase behaviors have automated verification."*
+
+---
+
+## Validation Sign-Off
+
+- [ ] All tasks have `<automated>` verify or Wave 0 dependencies
+- [ ] Sampling continuity: no 3 consecutive tasks without automated verify
+- [ ] Wave 0 covers all MISSING references
+- [ ] No watch-mode flags
+- [ ] Feedback latency < 13s
+- [ ] `nyquist_compliant: true` set in frontmatter
+
+**Approval:** {pending / approved YYYY-MM-DD}