diff --git a/packages/dashboard/app/components/WorkflowNodeEditor.css b/packages/dashboard/app/components/WorkflowNodeEditor.css
index 4aec798ec2..697b04b963 100644
--- a/packages/dashboard/app/components/WorkflowNodeEditor.css
+++ b/packages/dashboard/app/components/WorkflowNodeEditor.css
@@ -1398,6 +1398,7 @@
   .wf-editor-body--editor-stage .wf-editor-inspector {
     width: 100%;
     min-width: 0;
+    max-height: none;
     flex: 1 1 auto;
     min-height: 0;
     border-left: none;
diff --git a/packages/dashboard/app/components/__tests__/WorkflowNodeEditor.css.test.ts b/packages/dashboard/app/components/__tests__/WorkflowNodeEditor.css.test.ts
index 17605ecdf0..d71fdcb9d7 100644
--- a/packages/dashboard/app/components/__tests__/WorkflowNodeEditor.css.test.ts
+++ b/packages/dashboard/app/components/__tests__/WorkflowNodeEditor.css.test.ts
@@ -96,6 +96,7 @@ describe("WorkflowNodeEditor mobile CSS contract", () => {
 
     const inspectorRule = findRule(mobileBlocks, /\.wf-editor-body--editor-stage \.wf-editor-inspector\s*\{[^}]*\}/);
     expect(inspectorRule).toMatch(/width\s*:\s*100%\s*;/);
+    expect(inspectorRule).toMatch(/max-height\s*:\s*none\s*;/);
     expect(inspectorRule).toMatch(/flex\s*:\s*1 1 auto\s*;/);
     expect(inspectorRule).toMatch(/min-height\s*:\s*0\s*;/);
 
diff --git a/packages/dashboard/vitest.config.ts b/packages/dashboard/vitest.config.ts
index 676ff87fa5..95320c0178 100644
--- a/packages/dashboard/vitest.config.ts
+++ b/packages/dashboard/vitest.config.ts
@@ -231,7 +231,7 @@ const qualityAppComponentBatchBTests = buildComponentQualityInclude(batchedQuali
 const qualityAppAppOnlyTests = ["app/components/__tests__/App.test.tsx"];
 const qualityAppChatOnlyTests = ["app/components/__tests__/ChatView.test.tsx"];
 const qualityAppSettingsOnlyTests = ["app/components/__tests__/SettingsModal.test.tsx"];
-const quarantinedDashboardTests: string[] = [];
+const quarantinedDashboardTests: string[] = ["app/components/__tests__/Board.test.tsx"];
 
 const qualityApiTests = [
   // Critical HTTP/server behavior: auth, task/project/settings mutation,
diff --git a/scripts/lib/test-quarantine.json b/scripts/lib/test-quarantine.json
index 39eac9c428..4837cf4924 100644
--- a/scripts/lib/test-quarantine.json
+++ b/scripts/lib/test-quarantine.json
@@ -1,4 +1,10 @@
 {
   "$comment": "Flaky-test quarantine ledger (deletion ratchet — see AGENTS.md 'Flaky tests: quarantine on sight' and docs/testing.md 'Quarantine ledger and the deletion ratchet'). A test observed failing without a corresponding real bug is quarantined ON SIGHT: add an entry here AND a matching one-line `exclude` entry in that package's vitest config, in the same commit. Every entry needs a non-empty `reason` (link the failing run) and a `quarantinedAt` date — the entry expires 14 days later, at which point the test file is DELETED unless someone rescues it with evidence it catches real regressions plus a root-cause fix (never appeasement). There is deliberately no loader module and no automation around this file: it is a dated record, the vitest config exclude is the mechanism, and the sweep is policy executed by whoever touches the suite.",
-  "entries": []
+  "entries": [
+    {
+      "file": "packages/dashboard/app/components/__tests__/Board.test.tsx",
+      "reason": "FN-6154 local pnpm test run on 2026-06-09 failed in 'Board > multi-lane board (U9, flag ON) > preserves workflow toolbar partial action visibility' with missing .board-workflow-toolbar; unrelated to WorkflowNodeEditor CSS max-height change.",
+      "quarantinedAt": "2026-06-09"
+    }
+  ]
 }