Fix workflow key detection — use .key/.filename instead of .name

The ComfyUI activeWorkflow object doesn't have a .name property. It uses
.key (path minus workflows/ prefix) and .filename (no extension). The old
code always fell through to "default", making all snapshots share one key.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

js/snapshot_manager.js

@@ -199,7 +199,7 @@ function quickHash(str) {
 function getWorkflowKey() {
     try {
         const wf = app.workflowManager?.activeWorkflow;
-        return wf?.name || wf?.path || "default";
+        return wf?.key || wf?.filename || wf?.path || "default";
     } catch {
         return "default";
     }