feat: sitemap settings singleton with content types and additional addresses

- one settings tile opening the golem15.sitemap.settings singleton
- Files tab (site address, file size, S1 files partial), Additional
  addresses repeater, Content types tab built from signpost at boot
- golem15_sitemap_types; a type switched off leaves the files (reason type)
- a save validates (errors.*) and dispatches a rebuild after commit

go.mod

@@ -5,6 +5,7 @@ go 1.27.0
 require (
 	git.golem15.com/golem15/summercms v0.6.0
 	github.com/go-gormigrate/gormigrate/v2 v2.1.7
+	github.com/goccy/go-yaml v1.19.2
 	github.com/jackc/pgx/v5 v5.10.0
 	github.com/testcontainers/testcontainers-go v0.44.0
 	github.com/testcontainers/testcontainers-go/modules/postgres v0.44.0
@@ -75,7 +76,6 @@ require (
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/go-playground/validator/v10 v10.30.4 // indirect
 	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
-	github.com/goccy/go-yaml v1.19.2 // indirect
 	github.com/golang-jwt/jwt/v5 v5.3.1 // indirect
 	github.com/google/jsonschema-go v0.4.3 // indirect
 	github.com/google/uuid v1.6.0 // indirect