Fix ScadaBridge topology: bldg-5/19, no site-to-site, direct API access

- Warsaw West buildings corrected to 5 and 19 (was generic 3/7)
- Removed site-to-site direct routing (doesn't exist)
- Added external API callers with direct access to any site cluster
- Updated UNS hierarchy examples to use real building numbers
- Fixed current-state.md routing topology description

outputs/diagrams/scadabridge-topology.mmd

@@ -8,11 +8,11 @@ flowchart TB
 
     subgraph WarsawWest["Warsaw West Campus"]
         direction TB
-        subgraph WW3["Building 3 Cluster"]
-            WW3N1["Node 1"] <--> WW3N2["Node 2"]
+        subgraph WW5["Building 5 Cluster"]
+            WW5N1["Node 1"] <--> WW5N2["Node 2"]
         end
-        subgraph WW7["Building 7 Cluster"]
-            WW7N1["Node 1"] <--> WW7N2["Node 2"]
+        subgraph WW19["Building 19 Cluster"]
+            WW19N1["Node 1"] <--> WW19N2["Node 2"]
         end
     end
 
@@ -46,10 +46,13 @@ flowchart TB
     Central <-->|"hub route"| TMT
     Central <-->|"hub route"| Ponce
 
-    Shannon <-.->|"direct route<br/>(optional)"| Galway
+    API["External API Callers"] -.->|"direct access<br/>(any site cluster)"| Shannon
+    API -.-> WarsawWest
+    API -.-> Ponce
 
     subgraph Notes["Key: 2-node Akka.NET clusters, co-located on System Platform nodes"]
         L1["Hub-and-spoke: central routes to all sites"]
-        L2["Direct site-to-site routing available where needed"]
-        L3["Data locality: equipment talks to LOCAL cluster only"]
+        L2["No direct site-to-site routing"]
+        L3["API callers can reach site clusters directly"]
+        L4["Data locality: equipment talks to LOCAL cluster only"]
     end