fix(ci): pre-release uses updates_xml_build CLI with preserve logic

The inline PHP regex approach only updated existing entries — if no
matching channel entry existed, nothing was added. Now uses the
moko-platform CLI which creates new entries and preserves other channels.

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

.mokogitea/workflows/pre-release.yml

@@ -292,32 +292,17 @@ jobs:
 
           DOWNLOAD_URL="${GITEA_URL}/${GITEA_ORG}/${GITEA_REPO}/releases/download/${TAG}/${ZIP_NAME}"
 
-          # Use PHP to update the channel in updates.xml
-          php -r '
-            $xml_tag = $argv[1];
-            $version = $argv[2];
-            $sha256 = $argv[3];
-            $url = $argv[4];
-            $date = date("Y-m-d");
-
-            $content = file_get_contents("updates.xml");
-            $pattern = "/(<update>(?:(?!<\/update>).)*?<tag>" . preg_quote($xml_tag) . "<\/tag>.*?<\/update>)/s";
-
-            $content = preg_replace_callback($pattern, function($m) use ($version, $sha256, $url, $date) {
-              $block = $m[0];
-              $block = preg_replace("/<version>[^<]*<\/version>/", "<version>{$version}</version>", $block);
-              if (strpos($block, "<sha256>") !== false) {
-                $block = preg_replace("/<sha256>[^<]*<\/sha256>/", "<sha256>{$sha256}</sha256>", $block);
-              } else {
-                $block = str_replace("</downloads>", "</downloads>\n    <sha256>{$sha256}</sha256>", $block);
-              }
-              $block = preg_replace("/(<downloadurl[^>]*>)[^<]*(<\/downloadurl>)/", "\${1}{$url}\${2}", $block);
-              return $block;
-            }, $content);
-
-            file_put_contents("updates.xml", $content);
-            echo "Updated {$xml_tag} channel: version={$version}\n";
-          ' "$XML_TAG" "$VERSION" "$SHA256" "$DOWNLOAD_URL"
+          # Use moko-platform CLI to build/update updates.xml (preserves other channels)
+          MOKO_CLI="/tmp/moko-platform-api/cli"
+          if [ -f "${MOKO_CLI}/updates_xml_build.php" ]; then
+            php "${MOKO_CLI}/updates_xml_build.php" \
+              --path . --version "${VERSION}" --stability "${STABILITY}" \
+              --sha "${SHA256}" \
+              --gitea-url "${GITEA_URL}" --org "${GITEA_ORG}" --repo "${GITEA_REPO}"
+            echo "Updated ${STABILITY} channel via CLI: version=${VERSION}"
+          else
+            echo "WARNING: updates_xml_build.php not found — skipping"
+          fi
 
           # Commit and push
           if ! git diff --quiet updates.xml 2>/dev/null; then