step 1: rename module chat-switchboard → switchboard-core

- go.mod module name
- All 714 import references across 289 Go files
- VERSION: 0.1.0
- CI DB names: switchboard_core_{ci,dev,test}
- Docker image: gobha/switchboard-core
- Test fixtures: JWT issuer, repo names
- .env.example, docker-compose container name
- Compiles clean (go build exit 0)

docker-compose.yml

@@ -17,7 +17,7 @@ services:
     build:
       context: .
       dockerfile: Dockerfile
-    container_name: chat-switchboard
+    container_name: switchboard-core
     environment:
       PORT: "8080"
       BASE_PATH: ""