Add inbound Web API to ScadaBridge diagrams

Dataflow: inbound Web API (API key auth) added as a third input to scripts
Topology: API callers shown with two paths — direct to any site cluster
OR routed through central hub to reach sites

outputs/diagrams/scadabridge-dataflow.mmd

@@ -2,6 +2,7 @@ flowchart LR
     subgraph Inputs["Data Inputs"]
         OT["OtOpcUa<br/>Equipment NS"]
         SP["OtOpcUa<br/>System Platform NS"]
+        API_IN["Inbound Web API<br/>(API key auth)"]
     end
 
     subgraph ScadaBridge["ScadaBridge Cluster (per site)"]
@@ -27,6 +28,7 @@ flowchart LR
 
     OT --> SCR
     SP --> SCR
+    API_IN --> SCR
     TPL --> SCR
     SCR --> SAF
     SAF --> RED

outputs/diagrams/scadabridge-topology.mmd

@@ -46,13 +46,15 @@ flowchart TB
     Central <-->|"hub route"| TMT
     Central <-->|"hub route"| Ponce
 
-    API["External API Callers"] -.->|"direct access<br/>(any site cluster)"| Shannon
-    API -.-> WarsawWest
-    API -.-> Ponce
+    API["Inbound Web API Callers<br/>(API key auth)"]
+    API -.->|"direct to site"| Shannon
+    API -.->|"direct to site"| WarsawWest
+    API -.->|"direct to site"| Ponce
+    API -->|"or via central<br/>(routed to site)"| Central
 
     subgraph Notes["Key: 2-node Akka.NET clusters, co-located on System Platform nodes"]
         L1["Hub-and-spoke: central routes to all sites"]
         L2["No direct site-to-site routing"]
-        L3["API callers can reach site clusters directly"]
+        L3["Inbound API: direct to any site cluster OR routed through central"]
         L4["Data locality: equipment talks to LOCAL cluster only"]
     end