chore(rig): set ASPNETCORE_ENVIRONMENT on the site containers (register row 63)

The central containers have always set it; the six site containers never did,
so the Development-only DI scope validation from register row 50
(ServiceProviderValidation.Configure — ValidateScopes/ValidateOnBuild) was dead
on exactly the half of the topology that has six of the eight nodes. Program.cs
even carried a comment saying the site branch 'is the one that actually gains
coverage' while the rig gave it none; that comment is corrected here too.

Now that the site graph validates clean this buys live coverage: a captive
dependency or an unconstructible site-only descriptor fails the container at
boot instead of surfacing later as a mid-run resolve error.

Applied to all six docker/ site containers and both docker-env2/ site
containers, keeping the two rigs consistent. Dev/rig only — never production.

FILE EDITS ONLY: no docker command was run, and deploy.sh was not invoked.
Both compose files re-parsed with yaml.safe_load; all 8 + 4 services confirmed
to carry the expected env.

docker-env2/docker-compose.yml

@@ -70,6 +70,10 @@ services:
     container_name: scadabridge-env2-site-x-a
     environment:
       SCADABRIDGE_CONFIG: Site
+      # Register row 63 — mirrors docker/docker-compose.yml. Enables the Development-only
+      # DI scope validation (register row 50) on the site nodes, which previously ran
+      # unvalidated because only the central containers set this. Dev/rig only.
+      ASPNETCORE_ENVIRONMENT: Development
     ports:
       - "9121:8082"   # Akka remoting
       - "9123:8083"   # gRPC streaming
@@ -90,6 +94,10 @@ services:
     container_name: scadabridge-env2-site-x-b
     environment:
       SCADABRIDGE_CONFIG: Site
+      # Register row 63 — mirrors docker/docker-compose.yml. Enables the Development-only
+      # DI scope validation (register row 50) on the site nodes, which previously ran
+      # unvalidated because only the central containers set this. Dev/rig only.
+      ASPNETCORE_ENVIRONMENT: Development
     ports:
       - "9122:8082"   # Akka remoting
       - "9124:8083"   # gRPC streaming