feat(ui): persist expand state, GPU abnormal indicator, slower auto-refresh

- Remember history task and stdout/stderr terminal open state across the 60s refresh so they no longer collapse on every poll.
- Mark GPUs with allocated memory but near-zero utilization as `abnormal` (orange) — covers stuck processes that previously rendered as busy.
- Bump dashboard auto-refresh from 30s to 60s.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

public/styles.css

@@ -345,6 +345,11 @@ h3 {
   border-color: color-mix(in srgb, var(--good) 45%, transparent);
 }
 
+.gpu-thumb.abnormal {
+  background: color-mix(in srgb, var(--warn) 22%, transparent);
+  border-color: color-mix(in srgb, var(--warn) 50%, transparent);
+}
+
 .gpu-thumb.busy {
   background: color-mix(in srgb, var(--bad) 22%, transparent);
   border-color: color-mix(in srgb, var(--bad) 50%, transparent);