feat: add extra Docker networks to container config

Apps can now join additional Docker networks (e.g., monitoring,
prometheus) configured via containerConfig.extraNetworks. Flows through
the 3-layer config merge. Networks are created if absent and containers
are connected during deployment. UI adds a pill-list field on the
Resources tab (both create and edit views).

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

cameleer3-server-app/src/main/java/com/cameleer3/server/app/runtime/DeploymentExecutor.java

@@ -147,6 +147,16 @@ public class DeploymentExecutor {
                 additionalNets.add(envNet);
             }
 
+            // User-configured extra networks (e.g., monitoring)
+            if (networkManager != null && config.extraNetworks() != null) {
+                for (String net : config.extraNetworks()) {
+                    if (!net.isBlank() && !additionalNets.contains(net)) {
+                        networkManager.ensureNetwork(net);
+                        additionalNets.add(net);
+                    }
+                }
+            }
+
             // === START REPLICAS ===
             updateStage(deployment.id(), DeployStage.START_REPLICAS);
 
@@ -370,6 +380,7 @@ public class DeploymentExecutor {
         map.put("deploymentStrategy", config.deploymentStrategy());
         map.put("runtimeType", config.runtimeType());
         map.put("customArgs", config.customArgs());
+        map.put("extraNetworks", config.extraNetworks());
         return map;
     }
 }