Clean up AppURL, remove legacy origin-url webcomponent (#37090)

1. `origin-url` was introduced in the past when there was no good
framework support to detect current host url
    * It is not needed anymore
    * Removing it makes the code clearer
2. Separate template helper functions for different templates (web
page/mail)
3. The "AppURL" info is removed from admin config page: it doesn't
really help.
    * We already have various app url checks at many places

modules/templates/helper.go

@@ -25,8 +25,7 @@ import (
 	"code.gitea.io/gitea/services/gitdiff"
 )
 
-// NewFuncMap returns functions for injecting to templates
-func NewFuncMap() template.FuncMap {
+func newFuncMapWebPage() template.FuncMap {
 	return map[string]any{
 		"DumpVar": dumpVar,
 		"NIL":     func() any { return nil },
@@ -40,7 +39,6 @@ func NewFuncMap() template.FuncMap {
 		"QueryEscape":  queryEscape,
 		"QueryBuild":   QueryBuild,
 		"SanitizeHTML": SanitizeHTML,
-		"DotEscape":    dotEscape,
 
 		"PathEscape":         url.PathEscape,
 		"PathEscapeSegments": util.PathEscapeSegments,
@@ -61,6 +59,7 @@ func NewFuncMap() template.FuncMap {
 
 		// -----------------------------------------------------------------
 		// time / number / format
+		"ShortSha": base.ShortSha,
 		"FileSize": base.FileSize,
 		"CountFmt": countFmt,
 		"Sec2Hour": util.SecToHours,
@@ -73,6 +72,7 @@ func NewFuncMap() template.FuncMap {
 
 		"AssetURI":     public.AssetURI,
 		"ScriptImport": scriptImport,
+
 		// -----------------------------------------------------------------
 		// setting
 		"AppName": func() string {
@@ -84,17 +84,10 @@ func NewFuncMap() template.FuncMap {
 		"AssetUrlPrefix": func() string {
 			return setting.StaticURLPrefix + "/assets"
 		},
-		"AppUrl": func() string {
-			// The usage of AppUrl should be avoided as much as possible,
-			// because the AppURL(ROOT_URL) may not match user's visiting site and the ROOT_URL in app.ini may be incorrect.
-			// And it's difficult for Gitea to guess absolute URL correctly with zero configuration,
-			// because Gitea doesn't know whether the scheme is HTTP or HTTPS unless the reverse proxy could tell Gitea.
-			return setting.AppURL
-		},
 		"AppVer": func() string {
 			return setting.AppVer
 		},
-		"AppDomain": func() string { // documented in mail-templates.md
+		"AppDomain": func() string { // TODO: helm registry still uses it, need to use current request host in the future
 			return setting.Domain
 		},
 		"ShowFooterTemplateLoadTime": func() bool {
@@ -143,7 +136,6 @@ func NewFuncMap() template.FuncMap {
 
 		// -----------------------------------------------------------------
 		// misc (TODO: move them to MiscUtils to avoid bloating the main func map)
-		"ShortSha":                 base.ShortSha,
 		"ActionContent2Commits":    ActionContent2Commits,
 		"IsMultilineCommitMessage": isMultilineCommitMessage,
 		"CommentMustAsDiff":        gitdiff.CommentMustAsDiff,
@@ -177,11 +169,6 @@ func queryEscape(s string) template.URL {
 	return template.URL(url.QueryEscape(s))
 }
 
-// dotEscape wraps a dots in names with ZWJ [U+200D] in order to prevent auto-linkers from detecting these as urls
-func dotEscape(raw string) string {
-	return strings.ReplaceAll(raw, ".", "\u200d.\u200d")
-}
-
 // iif is an "inline-if", similar util.Iif[T] but templates need the non-generic version,
 // and it could be simply used as "{{iif expr trueVal}}" (omit the falseVal).
 func iif(condition any, vals ...any) any {