docs: Dashboard Principle + Landvex Dashboard audit prep

- DASHBOARD_PRINCIPLE.md (v1.0, LOCKED):

  - Four questions: What, Where, How serious, What now

  - Information hierarchy: Score -> Observations -> Map -> History -> Details

  - Decision Density: Dashboard = 1-3 decisions max

  - Not BI: helps user make decision, not consume statistics

  - Verification checklist

- EXPERIENCE_AUDIT_QA.md updated:

  - Screen 4: Landvex Dashboard (Phase: Manage)

  - Dashboard-specific questions: 3-second understanding, today's decision,

    80% ignorable, primary CTA

  - Dashboard Principle check: What/Where/How serious/What now

  - Decision Density target: 1-3 decisions

  - One-Sentence Test: understand area performance and what to act on

- Ready for Landvex Dashboard screen (stresstest for Foundation v1.0)

docs/design/EXPERIENCE_AUDIT_QA.md

@@ -240,14 +240,39 @@ If it takes two or three sentences, the screen is trying to do too much.
 
 ---
 
-## Screen 4: Dashboard (Placeholder)
+## Screen 4: Landvex Dashboard (Placeholder)
 
 **Product:** Landvex  
+**Phase:** Manage  
 **Status:** ⏳ Awaiting screen
 
+### Dashboard-Specific Questions
+
+| # | Question | Target |
+|---|----------|--------|
+| 1 | Can I understand the situation in 3 seconds? | Yes — score immediately visible |
+| 2 | What is today's most important decision? | Clear primary action |
+| 3 | Can I ignore 80% of the information? | Hierarchy: score → observations → map → history → details |
+| 4 | Is there a primary CTA? | "Inspect area" / "Order report" / "View changes" |
+
+### Dashboard Principle Check
+
+| Question | Target |
+|----------|--------|
+| What is happening? | Score + key changes |
+| Where is it happening? | Map or location indicator |
+| How serious is it? | Threshold comparison |
+| What do I do now? | Primary CTA |
+
+### Decision Density
+
+Target: 1–3 decisions
+
 ### One-Sentence Test
 
-Target: "I see what I've earned and what to do next."
+Target: "I understand how my area is performing and what to act on."
+
+If it takes two sentences, the dashboard is trying to do too much.
 
 ---