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)

server/database/database.go

@@ -12,7 +12,7 @@ import (
 	_ "github.com/lib/pq"
 	_ "modernc.org/sqlite"
 
-	"chat-switchboard/config"
+	"switchboard-core/config"
 )
 
 // DB is the application-wide database connection pool.