fix(updateserver): extract version from asset filename, omit client for packages

- Version now extracted from the zip asset filename first (most
  accurate), falling back to tag name then release title. Fixes
  mismatch where title version was updated but asset was stale.
- Omit <client> element for package extension types (packages manage
  their own sub-extension clients per Joomla spec).
- Make Client field omitempty so empty string doesn't render empty tag.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

services/updateserver/joomla.go

@@ -37,7 +37,7 @@ type xmlUpdate struct {
 	TargetPlatform xmlTargetPlat   `xml:"targetplatform"`
 	SHA256         string          `xml:"sha256,omitempty"`
 	SHA512         string          `xml:"sha512,omitempty"`
-	Client         string          `xml:"client"`
+	Client         string          `xml:"client,omitempty"`
 	PHPMinimum     string          `xml:"php_minimum,omitempty"`
 	Description    string          `xml:"description,omitempty"`
 	CreationDate   string          `xml:"creationDate,omitempty"`
@@ -286,7 +286,15 @@ func GenerateJoomlaXML(ctx context.Context, repo *repo_model.Repository, require
 			downloadURL = fmt.Sprintf("%s/archive/%s.zip", repoLink, rel.TagName)
 		}
 
-		version := extractVersion(rel.TagName)
+		// Extract version from the asset filename first (most accurate),
+		// then fall back to tag name, then release title.
+		version := ""
+		if zipName != "" {
+			version = extractVersion(zipName)
+		}
+		if version == "" {
+			version = extractVersion(rel.TagName)
+		}
 		// If the tag is a stream name (not a version), try the release title instead.
 		if version == "" || isStreamName(rel.TagName, streams) {
 			version = extractVersion(rel.Title)
@@ -313,12 +321,19 @@ func GenerateJoomlaXML(ctx context.Context, repo *repo_model.Repository, require
 			infoURL = cfg.InfoURL
 		}
 
+		// Joomla <client> element: only relevant for plugins/modules (site vs administrator).
+		// Packages manage their own sub-extension clients; omit for package type.
+		client := "site"
+		if extType == "package" {
+			client = ""
+		}
+
 		u := xmlUpdate{
 			Name:        displayName,
 			Description: desc,
 			Element:     element,
 			Type:        extType,
-			Client:      "site",
+			Client:      client,
 			Version:     version,
 			CreationDate: time.Unix(int64(rel.CreatedUnix), 0).Format("2006-01-02"),
 			InfoURL: xmlInfoURL{