feat(FN-2845): streamline node routing configuration in dashboard

- Add a reusable ProjectNodeSelector component and hook RoutingTab to it for per-task node overrides
- Move default node and unavailable-node policy controls into the dedicated Node Routing settings section
- Add descriptive routing guidance text and project-level note in SettingsModal
- Expand dashboard tests for routing tab behavior and node routing settings UX

packages/dashboard/app/components/RoutingTab.css

@@ -1,117 +1,34 @@
 .routing-tab {
-  display: flex;
-  flex-direction: column;
-  gap: var(--space-lg);
-}
-
-.routing-tab h4 {
-  margin: 0;
-}
-
-.routing-tab h5 {
-  margin: 0;
-  color: var(--text);
-}
-
-.routing-tab__intro {
-  margin: 0;
-  color: var(--text-muted);
-}
-
-.routing-tab__section {
-  display: flex;
-  flex-direction: column;
-  gap: var(--space-md);
-  padding: var(--space-lg);
-  border: 1px solid var(--border);
-  border-radius: var(--radius-md);
-  background: var(--card);
-}
-
-.routing-summary-grid {
-  display: grid;
-  gap: var(--space-sm);
-}
-
-.routing-summary-row {
-  display: grid;
-  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
-  gap: var(--space-md);
-  padding: var(--space-sm) 0;
-  border-bottom: 1px solid var(--border);
-}
-
-.routing-summary-row:last-child {
-  border-bottom: 0;
-}
-
-.routing-summary-label {
-  color: var(--text-muted);
-}
-
-.routing-summary-value {
-  display: inline-flex;
-  align-items: center;
-  gap: var(--space-sm);
-  color: var(--text);
-}
-
-.routing-summary-warning {
-  display: inline-flex;
-  align-items: center;
-  padding: 0 var(--space-sm);
-  border-radius: var(--radius-pill);
-  background: color-mix(in srgb, var(--color-warning) 16%, transparent);
-  color: var(--color-warning);
-}
-
-.routing-tab__info-banner,
-.routing-tab__warning-banner,
-.routing-tab__error {
-  padding: var(--space-sm) var(--space-md);
-  border-radius: var(--radius-sm);
-}
-
-.routing-tab__info-banner,
-.routing-tab__warning-banner {
-  background: color-mix(in srgb, var(--color-warning) 14%, transparent);
-  color: var(--color-warning);
-  border: 1px solid color-mix(in srgb, var(--color-warning) 35%, transparent);
-}
-
-.routing-tab__error {
-  background: var(--status-error-bg);
-  color: var(--color-error);
-  border: 1px solid color-mix(in srgb, var(--color-error) 40%, transparent);
-}
-
-.routing-tab__selector-label {
-  color: var(--text-muted);
-}
-
-.routing-tab__selector {
   width: 100%;
 }
 
-.routing-tab__override-row {
+.routing-tab-summary {
+  margin-bottom: var(--space-lg);
+}
+
+.routing-tab-override {
   display: flex;
-  align-items: center;
-  justify-content: space-between;
+  flex-direction: column;
   gap: var(--space-sm);
 }
 
-.routing-tab__override-text {
-  color: var(--text-muted);
+.routing-tab-blocked {
+  background: color-mix(in srgb, var(--color-warning) 10%, transparent);
+  color: var(--color-warning);
+  border: 1px solid color-mix(in srgb, var(--color-warning) 30%, transparent);
+  border-radius: var(--radius-md);
+  padding: var(--space-md) var(--space-lg);
+  font-size: 0.85rem;
+  margin-top: var(--space-sm);
+}
+
+.routing-tab-actions {
+  margin-top: var(--space-sm);
 }
 
 @media (max-width: 768px) {
-  .routing-summary-row {
-    grid-template-columns: minmax(0, 1fr);
-    gap: var(--space-xs);
-  }
-
-  .routing-tab__override-row {
-    flex-direction: column;
-    align-items: flex-start;
+  .routing-tab-summary,
+  .routing-tab-override {
+    margin-bottom: var(--space-md);
   }
 }