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+---
+phase: 7
+slug: multilanguage
+status: draft
+nyquist_compliant: false
+wave_0_complete: false
+created: 2026-03-25
+---
+
+# Phase 7 — Validation Strategy
+
+> Per-phase validation contract for feedback sampling during execution.
+
+---
+
+## Test Infrastructure
+
+| Property | Value |
+|----------|-------|
+| **Framework** | pytest 8.x + pytest-asyncio (existing) |
+| **Config file** | `pyproject.toml` (existing) |
+| **Quick run command** | `pytest tests/unit -x -q` |
+| **Full suite command** | `pytest tests/ -x` |
+| **Estimated runtime** | ~30 seconds |
+
+---
+
+## Sampling Rate
+
+- **After every task commit:** Run `pytest tests/unit -x -q`
+- **After every plan wave:** Run `pytest tests/ -x`
+- **Before `/gsd:verify-work`:** Full suite must be green
+- **Max feedback latency:** 30 seconds
+
+---
+
+## Per-Task Verification Map
+
+| Task ID | Plan | Wave | Requirement | Test Type | Automated Command | File Exists | Status |
+|---------|------|------|-------------|-----------|-------------------|-------------|--------|
+| 07-xx | 01 | 1 | I18N-03 | unit | `pytest tests/unit/test_system_prompt_builder.py -x` | ✅ extend | ⬜ pending |
+| 07-xx | 01 | 1 | I18N-02 | integration | `pytest tests/integration/test_language_preference.py -x` | ❌ W0 | ⬜ pending |
+| 07-xx | 01 | 1 | I18N-04 | integration | `pytest tests/integration/test_templates_i18n.py -x` | ❌ W0 | ⬜ pending |
+| 07-xx | 02 | 2 | I18N-01 | build | `cd packages/portal && npx next build` | ✅ | ⬜ pending |
+| 07-xx | 02 | 2 | I18N-02 | build | `cd packages/portal && npx next build` | ✅ | ⬜ pending |
+| 07-xx | 02 | 2 | I18N-06 | build | `cd packages/portal && npx next build` | ✅ | ⬜ pending |
+
+*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*
+
+---
+
+## Wave 0 Requirements
+
+- [ ] `tests/unit/test_system_prompt_builder.py` — extend with TestLanguageInstruction class (I18N-03)
+- [ ] `tests/integration/test_language_preference.py` — PATCH language endpoint (I18N-02)
+- [ ] `tests/integration/test_templates_i18n.py` — locale-aware templates endpoint (I18N-04)
+
+---
+
+## Manual-Only Verifications
+
+| Behavior | Requirement | Why Manual | Test Instructions |
+|----------|-------------|------------|-------------------|
+| Portal UI renders correctly in Spanish | I18N-01 | Browser rendering required | Switch to es, verify all labels/buttons translated |
+| Portal UI renders correctly in Portuguese | I18N-01 | Browser rendering required | Switch to pt, verify all labels/buttons translated |
+| Language switcher persists across sessions | I18N-02 | Requires login/logout cycle | Switch to es, log out, log back in, verify es persists |
+| Login page language switcher works pre-auth | I18N-02 | UI interaction | On login page, switch to pt, verify form labels change |
+| Agent responds in Spanish when messaged in Spanish | I18N-03 | Requires live LLM | Send Spanish message in chat, verify Spanish response |
+| Error messages display in selected language | I18N-05 | UI rendering | Trigger validation error in es locale, verify localized |
+
+---
+
+## 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 < 30s
+- [ ] `nyquist_compliant: true` set in frontmatter
+
+**Approval:** pending