docs(07): add validation strategy

.planning/phases/07-weight-unit-selection/07-VALIDATION.md

@@ -0,0 +1,77 @@
+---
+phase: 7
+slug: weight-unit-selection
+status: draft
+nyquist_compliant: false
+wave_0_complete: false
+created: 2026-03-16
+---
+
+# Phase 7 — Validation Strategy
+
+> Per-phase validation contract for feedback sampling during execution.
+
+---
+
+## Test Infrastructure
+
+| Property | Value |
+|----------|-------|
+| **Framework** | Bun test runner (built-in) |
+| **Config file** | None (uses bun defaults) |
+| **Quick run command** | `bun test` |
+| **Full suite command** | `bun test` |
+| **Estimated runtime** | ~5 seconds |
+
+---
+
+## Sampling Rate
+
+- **After every task commit:** Run `bun test`
+- **After every plan wave:** Run `bun test`
+- **Before `/gsd:verify-work`:** Full suite must be green
+- **Max feedback latency:** 5 seconds
+
+---
+
+## Per-Task Verification Map
+
+| Task ID | Plan | Wave | Requirement | Test Type | Automated Command | File Exists | Status |
+|---------|------|------|-------------|-----------|-------------------|-------------|--------|
+| 07-01-01 | 01 | 1 | UNIT-01 | unit | `bun test tests/routes/settings.test.ts` | No — Wave 0 | ⬜ pending |
+| 07-01-02 | 01 | 1 | UNIT-02 | unit | `bun test tests/lib/formatters.test.ts` | No — Wave 0 | ⬜ pending |
+| 07-01-03 | 01 | 1 | UNIT-03 | unit | `bun test tests/routes/settings.test.ts` | No — Wave 0 | ⬜ pending |
+
+*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*
+
+---
+
+## Wave 0 Requirements
+
+- [ ] `tests/lib/formatters.test.ts` — formatWeight with all 4 units, null handling, precision
+- [ ] `tests/routes/settings.test.ts` — settings API for weightUnit key (GET/PUT)
+
+*Existing test infrastructure (bun test, helpers/db.ts) covers framework setup.*
+
+---
+
+## Manual-Only Verifications
+
+| Behavior | Requirement | Why Manual | Test Instructions |
+|----------|-------------|------------|-------------------|
+| Unit toggle renders in TotalsBar | UNIT-01 | UI component rendering | Open app, verify g/oz/lb/kg toggle visible in TotalsBar |
+| All weight displays update on unit change | UNIT-02 | Visual verification across 8 components | Switch unit, check ItemCard, CandidateCard, CategoryHeader, SetupCard, setup detail, collection route |
+| Setting persists across browser refresh | UNIT-03 | Browser session state | Select "oz", refresh page, verify still shows "oz" |
+
+---
+
+## 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 < 5s
+- [ ] `nyquist_compliant: true` set in frontmatter
+
+**Approval:** pending