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/writers/template/safe_access.go

@@ -8,13 +8,13 @@ import (
 
 // Get safely gets a value from a map by key
 // Usage: {{ get .Metadata "key" }}
-func Get(m interface{}, key interface{}) interface{} {
+func Get(m, key interface{}) interface{} {
 	return reflectutil.MapGet(m, key)
 }
 
 // GetOr safely gets a value from a map with a default fallback
 // Usage: {{ getOr .Metadata "key" "default" }}
-func GetOr(m interface{}, key interface{}, defaultValue interface{}) interface{} {
+func GetOr(m, key, defaultValue interface{}) interface{} {
 	result := Get(m, key)
 	if result == nil {
 		return defaultValue
@@ -56,7 +56,7 @@ func SafeIndexOr(slice interface{}, index int, defaultValue interface{}) interfa
 
 // Has checks if a key exists in a map
 // Usage: {{ if has .Metadata "key" }}...{{ end }}
-func Has(m interface{}, key interface{}) bool {
+func Has(m, key interface{}) bool {
 	v := reflect.ValueOf(m)
 
 	// Dereference pointers
@@ -189,7 +189,7 @@ func Omit(m interface{}, keys ...interface{}) map[interface{}]interface{} {
 
 // SliceContains checks if a slice contains a value
 // Usage: {{ if sliceContains .Names "admin" }}...{{ end }}
-func SliceContains(slice interface{}, value interface{}) bool {
+func SliceContains(slice, value interface{}) bool {
 	v := reflect.ValueOf(slice)
 	v, ok := reflectutil.Deref(v)
 	if !ok {
@@ -211,7 +211,7 @@ func SliceContains(slice interface{}, value interface{}) bool {
 
 // IndexOf returns the index of a value in a slice, or -1 if not found
 // Usage: {{ $idx := indexOf .Names "admin" }}
-func IndexOf(slice interface{}, value interface{}) int {
+func IndexOf(slice, value interface{}) int {
 	v := reflect.ValueOf(slice)
 	v, ok := reflectutil.Deref(v)
 	if !ok {