refactor: remove pocketbase (#1138)

app/migration/migrations.go

@@ -0,0 +1,34 @@
+package migration
+
+import "fmt"
+
+var migrationGenerators = []func() (migration, error){
+	newSQLMigration("000_create_pocketbase_tables"),
+	newSQLMigration("001_create_tables"),
+	newFilesMigration(),
+	newSQLMigration("002_create_defaultdata"),
+	newSQLMigration("003_create_groups"),
+}
+
+func migrations(version int) ([]migration, error) {
+	var migrations []migration
+
+	if version < 0 || version > len(migrationGenerators) {
+		return nil, fmt.Errorf("invalid migration version: %d", version)
+	}
+
+	if version == len(migrationGenerators) {
+		return migrations, nil // No migrations to apply
+	}
+
+	for _, migrationFunc := range migrationGenerators[version:] {
+		migration, err := migrationFunc()
+		if err != nil {
+			return nil, fmt.Errorf("failed to create migration: %w", err)
+		}
+
+		migrations = append(migrations, migration)
+	}
+
+	return migrations, nil
+}