Extract shared utilities into workspace package (#5843)

## Summary

Extracts shared formatting and network utilities into dedicated
workspace package.

## Changes

- **What**: Created `@comfyorg/shared-frontend-utils` package containing
formatUtil and networkUtil
- **Breaking**: None - utilities remain accessible via path aliases in
`tsconfig`

Split `createAnnotatedPath` and `electronMirrorCheck` out and left in
frontend, due to their tightly-coupled nature. See [discussion on this
PR](https://github.com/Comfy-Org/ComfyUI_frontend/pull/5843#issuecomment-3344724727).

packages/shared-frontend-utils/package.json

@@ -0,0 +1,22 @@
+{
+  "name": "@comfyorg/shared-frontend-utils",
+  "private": true,
+  "version": "1.0.0",
+  "description": "Shared frontend utils for ComfyUI Frontend",
+  "scripts": {
+    "typecheck": "tsc --noEmit"
+  },
+  "keywords": [],
+  "packageManager": "pnpm@10.17.1",
+  "type": "module",
+  "exports": {
+    "./formatUtil": "./src/formatUtil.ts",
+    "./networkUtil": "./src/networkUtil.ts"
+  },
+  "dependencies": {
+    "axios": "^1.11.0"
+  },
+  "devDependencies": {
+    "typescript": "^5.9.2"
+  }
+}