fix(dashboard): unified solid edges, hide FALLBACK labels, conditional cursor (#247 Phase 1)

What: Restore graph visual preferences — all edges solid, FALLBACK labels hidden,
inactive nodes not clickable.

Why: Visual consistency and cleaner graph appearance per design preferences.

Changes:
- condition-edge.tsx: remove strokeDasharray, unify stroke color, hide FALLBACK labels
- role-node.tsx: cursor-pointer only on non-default state nodes

Ref: #247, closes #248

packages/workflow-dashboard/src/components/workflow-graph/condition-edge.tsx

@@ -78,9 +78,8 @@ export function ConditionEdge(props: EdgeProps) {
     defaultLabelY = result[2];
   }
 
-  const stroke = isFallback ? "var(--color-text-muted)" : "var(--color-accent)";
-  const strokeDasharray = isFallback ? "5 4" : undefined;
-  const label = edgeData?.condition ?? "";
+  const stroke = "var(--color-accent)";
+  const label = isFallback ? "" : (edgeData?.condition ?? "");
 
   // Use pre-computed label position if available, otherwise fall back to default
   const labelX = edgeData?.labelX ?? defaultLabelX;
@@ -92,7 +91,7 @@ export function ConditionEdge(props: EdgeProps) {
         id={id}
         path={path}
         markerEnd={markerEnd}
-        style={{ stroke, strokeWidth: 1.5, strokeDasharray }}
+        style={{ stroke, strokeWidth: 1.5 }}
       />
       {label !== "" && (
         <EdgeLabelRenderer>
@@ -102,7 +101,7 @@ export function ConditionEdge(props: EdgeProps) {
               transform: `translate(-50%, -50%) translate(${labelX}px, ${labelY}px)`,
               background: "var(--color-surface)",
               border: "1px solid var(--color-border)",
-              color: isFallback ? "var(--color-text-muted)" : "var(--color-text)",
+              color: "var(--color-text)",
               whiteSpace: "nowrap",
               zIndex: 10,
             }}

packages/workflow-dashboard/src/components/workflow-graph/role-node.tsx

@@ -31,7 +31,7 @@ export function RoleNode(props: NodeProps) {
 
   return (
     <div
-      className={`px-3 py-2 rounded-md border-2 text-xs font-medium cursor-pointer ${isActive ? "wf-node-pulse" : ""}`}
+      className={`px-3 py-2 rounded-md border-2 text-xs font-medium ${t.state !== "default" ? "cursor-pointer" : ""} ${isActive ? "wf-node-pulse" : ""}`}
       style={{
         width: 180,
         height: 60,