diff --git a/.planning/config.json b/.planning/config.json
index d436d0c..be92de0 100644
--- a/.planning/config.json
+++ b/.planning/config.json
@@ -25,7 +25,8 @@
     "text_mode": false,
     "research_before_questions": false,
     "discuss_mode": "discuss",
-    "skip_discuss": false
+    "skip_discuss": false,
+    "_auto_chain_active": false
   },
   "hooks": {
     "context_warnings": true
diff --git a/.planning/phases/01-architecture-foundation/01-VALIDATION.md b/.planning/phases/01-architecture-foundation/01-VALIDATION.md
new file mode 100644
index 0000000..54d9074
--- /dev/null
+++ b/.planning/phases/01-architecture-foundation/01-VALIDATION.md
@@ -0,0 +1,77 @@
+---
+phase: 1
+slug: architecture-foundation
+status: draft
+nyquist_compliant: false
+wave_0_complete: false
+created: 2026-03-27
+---
+
+# Phase 1 — Validation Strategy
+
+> Per-phase validation contract for feedback sampling during execution.
+
+---
+
+## Test Infrastructure
+
+| Property | Value |
+|----------|-------|
+| **Framework** | dotnet test (built-in) |
+| **Config file** | none — Wave 0 installs |
+| **Quick run command** | `dotnet build` |
+| **Full suite command** | `dotnet build && dotnet publish src/ChatAgent.Client/ChatAgent.Client.csproj` |
+| **Estimated runtime** | ~15 seconds |
+
+---
+
+## Sampling Rate
+
+- **After every task commit:** Run `dotnet build`
+- **After every plan wave:** Run `dotnet build && dotnet publish src/ChatAgent.Client/ChatAgent.Client.csproj`
+- **Before `/gsd:verify-work`:** Full suite must be green
+- **Max feedback latency:** 15 seconds
+
+---
+
+## Per-Task Verification Map
+
+| Task ID | Plan | Wave | Requirement | Test Type | Automated Command | File Exists | Status |
+|---------|------|------|-------------|-----------|-------------------|-------------|--------|
+| 01-01-01 | 01 | 1 | CODE-01 | build | `dotnet build` | ❌ W0 | ⬜ pending |
+| 01-01-02 | 01 | 1 | CODE-01 | build | `dotnet build` | ❌ W0 | ⬜ pending |
+| 01-02-01 | 02 | 1 | CODE-02 | build+run | `dotnet build && dotnet run --project src/ChatAgent.Api` | ❌ W0 | ⬜ pending |
+| 01-02-02 | 02 | 2 | CODE-02 | publish | `dotnet publish src/ChatAgent.Client/ChatAgent.Client.csproj` | ❌ W0 | ⬜ pending |
+
+*Status: ⬜ pending · ✅ green · ❌ red · ⚠️ flaky*
+
+---
+
+## Wave 0 Requirements
+
+- [ ] Solution and projects created via `dotnet new` commands
+- [ ] All three projects buildable with `dotnet build`
+
+*If none: "Existing infrastructure covers all phase requirements."*
+
+---
+
+## Manual-Only Verifications
+
+| Behavior | Requirement | Why Manual | Test Instructions |
+|----------|-------------|------------|-------------------|
+| CORS working end-to-end | CODE-01 | Requires both projects running simultaneously | Start API, start Client, verify client can reach API endpoint |
+| Tutorial comments present | CODE-02 | Content quality check | Review each file for inline Blazor concept explanations |
+
+---
+
+## 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