chore(ci): add govulncheck, staticcheck, go vet, gofumpt gates

* Add lint/format checks to the Gitea release workflow and Makefile
  (targets: vet, fmt, fmt-check, staticcheck, govulncheck, check)
* Switch .golangci.json formatter from gofmt to gofumpt (extra.group-params)
* Bump golang.org/x/text 0.37.0 -> 0.39.0 for GO-2026-5970; re-vendor
* Fix staticcheck S1011 in pkg/diff; drop unused pgsql writer helpers
* Fix gocritic unnamedResult (pkg/diff) and rangeValCopy (pkg/pgsql)
* Apply gofumpt + goimports formatting across the tree

pkg/readers/dbml/reader.go

@@ -701,7 +701,7 @@ func (r *Reader) parseColumn(line, tableName, schemaName string) (*models.Column
 	return column, constraint
 }
 
-func splitInlineComment(line string) (content string, inlineComment string) {
+func splitInlineComment(line string) (content, inlineComment string) {
 	commentStart := strings.Index(line, "//")
 	if commentStart == -1 {
 		return line, ""
@@ -710,7 +710,7 @@ func splitInlineComment(line string) (content string, inlineComment string) {
 	return strings.TrimSpace(line[:commentStart]), strings.TrimSpace(line[commentStart+2:])
 }
 
-func splitColumnSignatureAndAttrs(line string) (signature string, attrs string) {
+func splitColumnSignatureAndAttrs(line string) (signature, attrs string) {
 	trimmed := strings.TrimSpace(line)
 	if trimmed == "" || !strings.HasSuffix(trimmed, "]") {
 		return trimmed, ""
@@ -736,7 +736,7 @@ func splitColumnSignatureAndAttrs(line string) (signature string, attrs string)
 	return trimmed, ""
 }
 
-func parseColumnSignature(signature string) (columnName string, columnType string, ok bool) {
+func parseColumnSignature(signature string) (columnName, columnType string, ok bool) {
 	signature = strings.TrimSpace(signature)
 	if signature == "" {
 		return "", "", false
@@ -1041,5 +1041,5 @@ func (r *Reader) parseTableRef(ref string) (schema, table string, columns []stri
 		table = stripQuotes(parts[0])
 	}
 
-	return
+	return schema, table, columns
 }