feat: redesign exchange detail page with interactive processor inspector

- Rewrite ExchangeDetail with split Message IN/OUT panels that update
  on processor click, error panel for failed processors, and
  Timeline/Flow toggle for the processor visualization
- Add correlation chain in header with status-colored clickable nodes
  sorted by start time, labeled "Correlated Exchanges"
- Add Exchange ID column and inspect button (↗) to Dashboard table
- Add "Open full details" link in the exchange slide-in panel
- Add selectedIndex prop to ProcessorTimeline and RouteFlow for
  highlighting the active processor
- Add onNodeClick + selectedIndex to RouteFlow for interactive use
- Add correlationGroup field to exchange mock data
- Fix sidebar section toggle indentation alignment

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

src/pages/Dashboard/Dashboard.module.css

@@ -223,3 +223,43 @@
   font-family: var(--font-mono);
   word-break: break-word;
 }
+
+/* Inspect exchange icon in table */
+.inspectLink {
+  background: transparent;
+  border: none;
+  color: var(--text-faint);
+  opacity: 0.75;
+  cursor: pointer;
+  font-size: 13px;
+  padding: 2px 4px;
+  border-radius: var(--radius-sm);
+  line-height: 1;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  transition: color 0.15s, opacity 0.15s;
+}
+
+.inspectLink:hover {
+  color: var(--text-primary);
+  opacity: 1;
+}
+
+/* Open full details link in panel */
+.openDetailLink {
+  background: transparent;
+  border: none;
+  color: var(--amber);
+  cursor: pointer;
+  font-size: 12px;
+  padding: 0;
+  font-family: var(--font-body);
+  transition: color 0.1s;
+}
+
+.openDetailLink:hover {
+  color: var(--amber-deep);
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}