feat: use endpointUri for cross-route drill-down instead of label parsing

Server:
- Add endpointUri to PositionedNode (from RouteNode)
- Add fromEndpointUri to RouteSummary (catalog API)
- Catalog controller resolves endpoint URI from diagram store

UI:
- Build endpointRouteMap from catalog's fromEndpointUri field
- Drill-down uses exact match on node.endpointUri against the map
- Remove label parsing heuristics (extractTargetEndpoint, camelToKebab)

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

cameleer3-server-core/src/main/java/com/cameleer3/server/core/diagram/PositionedNode.java

@@ -8,14 +8,15 @@ import java.util.List;
  * For compound nodes (CHOICE, SPLIT, TRY_CATCH, etc.), {@code children}
  * contains the nested child nodes rendered inside the parent bounds.
  *
- * @param id       node identifier (matches RouteNode.id)
- * @param label    display label
- * @param type     NodeType name (e.g., "ENDPOINT", "PROCESSOR")
- * @param x        horizontal position
- * @param y        vertical position
- * @param width    node width
- * @param height   node height
- * @param children nested child nodes for compound/swimlane groups
+ * @param id          node identifier (matches RouteNode.id)
+ * @param label       display label
+ * @param type        NodeType name (e.g., "ENDPOINT", "PROCESSOR")
+ * @param x           horizontal position
+ * @param y           vertical position
+ * @param width       node width
+ * @param height      node height
+ * @param children    nested child nodes for compound/swimlane groups
+ * @param endpointUri the Camel endpoint URI (e.g., "direct:processOrder"), null for non-endpoint nodes
  */
 public record PositionedNode(
         String id,
@@ -25,6 +26,7 @@ public record PositionedNode(
         double y,
         double width,
         double height,
-        List<PositionedNode> children
+        List<PositionedNode> children,
+        String endpointUri
 ) {
 }