Change schema_migrations version from TEXT to INTEGER

internal/database/database.go

@@ -9,6 +9,7 @@ import (
 	"log/slog"
 	"path/filepath"
 	"sort"
+	"strconv"
 	"strings"
 
 	"go.uber.org/fx"
@@ -23,7 +24,7 @@ var schemaFS embed.FS
 
 // bootstrapVersion is the migration that creates the schema_migrations
 // table itself. It is applied before the normal migration loop.
-const bootstrapVersion = "000"
+const bootstrapVersion = 0
 
 // Params defines dependencies for Database.
 type Params struct {
@@ -42,35 +43,40 @@ type Database struct {
 // ParseMigrationVersion extracts the numeric version prefix from a migration
 // filename. Filenames must follow the pattern "<version>.sql" or
 // "<version>_<description>.sql", where version is a zero-padded numeric
-// string (e.g. "001", "002"). Returns the version string and an error if
-// the filename does not match the expected pattern.
-func ParseMigrationVersion(filename string) (string, error) {
+// string (e.g. "001", "002"). Returns the version as an integer and an
+// error if the filename does not match the expected pattern.
+func ParseMigrationVersion(filename string) (int, error) {
 	name := strings.TrimSuffix(filename, filepath.Ext(filename))
 	if name == "" {
-		return "", fmt.Errorf("invalid migration filename %q: empty name", filename)
+		return 0, fmt.Errorf("invalid migration filename %q: empty name", filename)
 	}
 
 	// Split on underscore to separate version from description.
 	// If there's no underscore, the entire stem is the version.
-	version := name
+	versionStr := name
 	if idx := strings.IndexByte(name, '_'); idx >= 0 {
-		version = name[:idx]
+		versionStr = name[:idx]
 	}
 
-	if version == "" {
-		return "", fmt.Errorf("invalid migration filename %q: empty version prefix", filename)
+	if versionStr == "" {
+		return 0, fmt.Errorf("invalid migration filename %q: empty version prefix", filename)
 	}
 
 	// Validate the version is purely numeric.
-	for _, ch := range version {
+	for _, ch := range versionStr {
 		if ch < '0' || ch > '9' {
-			return "", fmt.Errorf(
+			return 0, fmt.Errorf(
 				"invalid migration filename %q: version %q contains non-numeric character %q",
-				filename, version, string(ch),
+				filename, versionStr, string(ch),
 			)
 		}
 	}
 
+	version, err := strconv.Atoi(versionStr)
+	if err != nil {
+		return 0, fmt.Errorf("invalid migration filename %q: %w", filename, err)
+	}
+
 	return version, nil
 }