style: refine protocol tabs and adaptive usage table layout

- Simplify protocol selection with subtle accent backgrounds and clear focus states
- Remove conflicting workspace styles from protocol tabs
- Expand usage tables to fill available width while preserving horizontal scrolling
- Allow token metrics to wrap in narrow columns

src/pages/UsageEventsView.css

@@ -91,7 +91,8 @@
 }
 
 .usage-request-log .usage-events-table {
-  min-width: 0;
+  /* Fill spare space proportionally while retaining saved widths on narrow screens. */
+  min-width: 100%;
   font-size: 12px;
   font-variant-numeric: tabular-nums;
 }
@@ -202,8 +203,9 @@
 
 .usage-request-log .usage-event-metrics {
   display: flex;
+  flex-wrap: wrap;
   align-items: center;
-  gap: 9px;
+  gap: 3px 9px;
   margin-top: 3px;
   font-size: 10px;
   font-weight: 500;