fix(workflow): hide idle nested subflow end handles (#6976)

* fix(workflow): hide idle nested subflow end handles

* perf(workflow): avoid repeated subflow edge scans

* perf(workflow): stabilize subflow edge selector

---------

Co-authored-by: Bill Leoutsakos <billleoutsakos@Bills-MacBook-Pro.local>
Co-authored-by: Waleed Latif <walif6@gmail.com>

apps/docs/package.json

@@ -10,6 +10,7 @@
     "build": "fumadocs-mdx && NODE_OPTIONS='--max-old-space-size=8192' next build",
     "start": "next start",
     "postinstall": "fumadocs-mdx",
+    "test": "vitest run",
     "type-check": "fumadocs-mdx && tsc --noEmit",
     "lint": "biome check --write --unsafe .",
     "lint:check": "biome check .",
@@ -47,6 +48,7 @@
     "@types/react-dom": "^19.0.4",
     "postcss": "^8.5.3",
     "tailwindcss": "^4.0.12",
-    "typescript": "^7.0.2"
+    "typescript": "^7.0.2",
+    "vitest": "^4.1.0"
   }
 }