Add ensureReleaseTags: create development/beta/release-candidate tags on sync

Ensures all repos have standard release channel tags pointing to
the default branch. Tags are created if missing, skipped if they exist.

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

automation/bulk_sync.php

@@ -379,6 +379,7 @@ class BulkSync extends CLIApp
             // (e.g. 54 new labels on a fresh repo), reset it so file sync proceeds.
             if (!$this->dryRun) {
                 $this->ensureRepoLabels($org, $repoName);
+                $this->ensureReleaseTags($org, $repoName);
                 $this->api->resetCircuitBreaker();
             }
 
@@ -958,8 +959,51 @@ class BulkSync extends CLIApp
     }
 
     /**
-     * Create a tracking issue in the target repository after a successful sync.
+     * Ensure standard release tags exist on the repository.
      *
+     * Creates 'development', 'beta', and 'release-candidate' tags pointing
+     * to the default branch HEAD if they don't already exist. These tags
+     * are used by the release workflow to track stability channels.
+     */
+    private function ensureReleaseTags(string $org, string $repo): void
+    {
+        $requiredTags = ['development', 'beta', 'release-candidate'];
+
+        try {
+            $existingTags = $this->api->get("/repos/{$org}/{$repo}/tags", ['limit' => 50]);
+        } catch (\Exception $e) {
+            return; // Non-critical
+        }
+
+        $existingNames = array_column($existingTags, 'name');
+
+        // Get default branch to point new tags at
+        try {
+            $repoInfo = $this->api->get("/repos/{$org}/{$repo}");
+            $defaultBranch = $repoInfo['default_branch'] ?? 'main';
+        } catch (\Exception $e) {
+            $defaultBranch = 'main';
+        }
+
+        foreach ($requiredTags as $tagName) {
+            if (in_array($tagName, $existingNames, true)) {
+                continue;
+            }
+
+            try {
+                $this->api->post("/repos/{$org}/{$repo}/tags", [
+                    'tag_name' => $tagName,
+                    'target'   => $defaultBranch,
+                    'message'  => "Release channel: {$tagName}",
+                ]);
+                $this->log("  🏷️  Created tag '{$tagName}' on {$repo}", 'INFO');
+            } catch (\Exception $e) {
+                // Non-critical — tag may already exist as a release tag
+            }
+        }
+    }
+
+    /**
      * Merge main into all open PR branches (except the sync branch itself).
      *
      * This ensures feature/development branches stay up to date with the