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/graphql/type_mapping.go

@@ -32,7 +32,7 @@ func (r *Reader) isScalarType(typeName string, ctx *parseContext) bool {
 	return commonCustomScalars[typeName]
 }
 
-func (r *Reader) graphQLTypeToSQL(gqlType string, fieldName string, typeName string) string {
+func (r *Reader) graphQLTypeToSQL(gqlType, fieldName, typeName string) string {
 	// Check for ID type with configurable mapping
 	if gqlType == "ID" {
 		// Check metadata for ID type preference