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/handlers/task_test.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"testing"
 
-	"chat-switchboard/database"
+	"switchboard-core/database"
 )
 
 // ═══════════════════════════════════════════════
@@ -444,7 +444,7 @@ func TestTask_TriggerEndpoint(t *testing.T) {
 	w = h.request("POST", "/api/v1/hooks/t/"+triggerToken, "", map[string]interface{}{
 		"build_id": 12345,
 		"status":   "failed",
-		"repo":     "chat-switchboard",
+		"repo":     "switchboard-core",
 	})
 	if w.Code != http.StatusAccepted {
 		t.Fatalf("trigger: want 202, got %d: %s", w.Code, w.Body.String())