feat(ui): add license usage visualization with progress bars

Split license limits into metered "Resource Usage" (with color-coded
progress bars) and static "Plan Limits" cards. Updated UsageIndicator
with 8px bars, green/amber/red thresholds, and tabular-nums formatting.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/styles/platform.module.css

@@ -61,3 +61,42 @@
   word-break: break-all;
   white-space: pre-wrap;
 }
+
+/* Usage progress bar */
+.usageRow {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  padding: 6px 0;
+}
+
+.usageHeader {
+  display: flex;
+  justify-content: space-between;
+  align-items: baseline;
+}
+
+.usageLabel {
+  font-size: 0.8125rem;
+  font-weight: 500;
+  color: var(--text-primary);
+}
+
+.usageValue {
+  font-size: 0.75rem;
+  font-variant-numeric: tabular-nums;
+  color: var(--text-secondary);
+}
+
+.usageBarTrack {
+  height: 8px;
+  border-radius: 4px;
+  background: var(--bg-inset);
+  overflow: hidden;
+}
+
+.usageBarFill {
+  height: 100%;
+  border-radius: 4px;
+  transition: width 0.4s ease, background-color 0.3s ease;
+}