fix: unify goose Provider path and fail on pending migrations

Apply BasePath via fs.Sub, route CLI through Provider API, return
ErrPendingMigrations when auto-migrate is disabled, use DownTo for blank.

Co-authored-by: Cursor <cursoragent@cursor.com>

migrate_test.go

@@ -0,0 +1,18 @@
+package migrate_test
+
+import (
+	"testing"
+
+	"gitea.auvem.com/go-toolkit/migrate"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestModuleMigrationsRequiresConfig(t *testing.T) {
+	_, err := migrate.ModuleMigrations(nil)
+	assert.Error(t, err)
+	assert.ErrorIs(t, err, migrate.ErrInvalidMigrationCfg)
+}
+
+func TestErrPendingMigrations(t *testing.T) {
+	assert.Error(t, migrate.ErrPendingMigrations)
+}