docs(33): add research, validation strategy, and UI design contract

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.planning/phases/33-currency-system/33-VALIDATION.md

@@ -0,0 +1,82 @@
+---
+phase: 33
+slug: currency-system
+status: draft
+nyquist_compliant: false
+wave_0_complete: false
+created: 2026-04-13
+---
+
+# Phase 33 — Validation Strategy
+
+> Per-phase validation contract for feedback sampling during execution.
+
+---
+
+## Test Infrastructure
+
+| Property | Value |
+|----------|-------|
+| **Framework** | Bun test runner + Playwright |
+| **Config file** | `bunfig.toml` / `playwright.config.ts` |
+| **Quick run command** | `bun test` |
+| **Full suite command** | `bun test && bun run test:e2e` |
+| **Estimated runtime** | ~15 seconds (unit) + ~60 seconds (e2e) |
+
+---
+
+## Sampling Rate
+
+- **After every task commit:** Run `bun test`
+- **After every plan wave:** Run `bun test && bun run test:e2e`
+- **Before `/gsd-verify-work`:** Full suite must be green
+- **Max feedback latency:** 15 seconds
+
+---
+
+## Per-Task Verification Map
+
+| Task ID | Plan | Wave | Requirement | Threat Ref | Secure Behavior | Test Type | Automated Command | File Exists | Status |
+|---------|------|------|-------------|------------|-----------------|-----------|-------------------|-------------|--------|
+| 33-01-01 | 01 | 1 | D-01, D-02 | — | N/A | unit | `bun test tests/services/currency.service.test.ts` | ❌ W0 | ⬜ pending |
+| 33-01-02 | 01 | 1 | D-08, D-09 | — | N/A | unit | `bun test tests/services/currency.service.test.ts` | ❌ W0 | ⬜ pending |
+| 33-02-01 | 02 | 2 | D-01 | — | N/A | integration | `bun test tests/services/market-price.service.test.ts` | ❌ W0 | ⬜ pending |
+| 33-02-02 | 02 | 2 | D-04, D-05 | — | Ownership validation | integration | `bun test tests/services/community-price.service.test.ts` | ❌ W0 | ⬜ pending |
+| 33-03-01 | 03 | 3 | D-12, D-14 | — | N/A | unit | `bun test tests/lib/formatters.test.ts` | ❌ W0 | ⬜ pending |
+| 33-03-02 | 03 | 3 | D-16 | — | N/A | e2e | `bun run test:e2e --grep "currency"` | ❌ W0 | ⬜ pending |
+
+*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*
+
+---
+
+## Wave 0 Requirements
+
+- [ ] `tests/services/currency.service.test.ts` — stubs for rate fetching, caching, conversion
+- [ ] `tests/services/market-price.service.test.ts` — stubs for market price CRUD
+- [ ] `tests/services/community-price.service.test.ts` — stubs for community price submission + ownership validation
+- [ ] `tests/lib/formatters.test.ts` — stubs for dual display format, conversion labels
+
+*Existing test infrastructure (Bun test runner, createTestDb helper) covers framework needs.*
+
+---
+
+## Manual-Only Verifications
+
+| Behavior | Requirement | Why Manual | Test Instructions |
+|----------|-------------|------------|-------------------|
+| Auto-suggestion via browser locale | D-13 | Requires browser environment with locale | Open app in incognito, verify suggestion matches browser locale |
+| Dual display format readability | D-14 | Visual check | Verify converted prices show `€2,000 (~$2,160)` format |
+| Community price aggregation display | D-21 | Requires seeded community data | Seed 3+ price reports, verify "Users in DE typically pay..." display |
+
+---
+
+## 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 < 15s
+- [ ] `nyquist_compliant: true` set in frontmatter
+
+**Approval:** pending