fix: review — stable sort fallback, cleaner status colors

- Sort: threads without startedAt pushed to bottom (not random)
- Colors: completed=success(green), running/active=accent(blue), failed=error(red)
- Remove opacity hack, simplify ternary

小橘 <xiaoju@shazhou.work>

packages/workflow-dashboard/src/components/thread-list.tsx

@@ -14,7 +14,9 @@ export function ThreadList({ agent, onSelect }: Props) {
   if (status === "error") return <p style={{ color: "var(--color-error)" }}>Error: {error}</p>;
 
   const threads = [...data.threads].sort((a, b) => {
-    if (!a.startedAt || !b.startedAt) return 0;
+    if (!a.startedAt && !b.startedAt) return 0;
+    if (!a.startedAt) return 1;
+    if (!b.startedAt) return -1;
     return b.startedAt.localeCompare(a.startedAt);
   });
 
@@ -42,15 +44,12 @@ export function ThreadList({ agent, onSelect }: Props) {
                     className="text-xs px-2 py-0.5 rounded"
                     style={{
                       background:
-                        t.status === "running"
+                        t.status === "completed"
                           ? "var(--color-success)"
                           : t.status === "failed"
                             ? "var(--color-error)"
-                            : t.status === "completed"
-                              ? "var(--color-success)"
-                              : "var(--color-accent)",
+                            : "var(--color-accent)",
                       color: "#000",
-                      opacity: t.status === "completed" ? 0.7 : 1,
                     }}
                   >
                     {t.status}