Claude-assisted improvements (untested)

- dev auth flow (side-step OAuth)
- db event processing integration tests
- dev scripts (eg Makefile)
- db / test db migration setup scripts.

database.go

@@ -7,8 +7,8 @@ import (
 	"github.com/jackc/pgx/v5/pgxpool"
 )
 
-func newPool(ctx context.Context) (*pgxpool.Pool, error) {
-	pool, err := pgxpool.New(ctx, "postgres://app_client:app_password@localhost:5432/inventory_2?sslmode=disable")
+func newPool(ctx context.Context, databaseURL string) (*pgxpool.Pool, error) {
+	pool, err := pgxpool.New(ctx, databaseURL)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create database client: %w", err)
 	}