fix: update api import paths & fix Dockerfile not copying frontend build

fixes issue #7 & #9

also remove agGrid dependency from package.json to reduce download size

internal/graph/schema.resolvers.go

@@ -11,7 +11,7 @@ import (
 	"time"
 
 	"github.com/google/uuid"
-	"github.com/jordanknott/project-citadel/api/internal/db"
+	"github.com/jordanknott/project-citadel/internal/db"
 	log "github.com/sirupsen/logrus"
 	"github.com/vektah/gqlparser/v2/gqlerror"
 	"golang.org/x/crypto/bcrypt"