fix: prevent asset conflicts between React and Grid.js versions

Add coexistence checks to all enqueue methods to prevent loading
both React and Grid.js assets simultaneously.

Changes:
- ReactAdmin.php: Only enqueue React assets when ?react=1
- Init.php: Skip Grid.js when React active on admin pages
- Form.php, Coupon.php, Access.php: Restore classic assets when ?react=0
- Customer.php, Product.php, License.php: Add coexistence checks

Now the toggle between Classic and React versions works correctly.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

node_modules/pac-proxy-agent/node_modules/https-proxy-agent/package.json

@@ -0,0 +1,50 @@
+{
+  "name": "https-proxy-agent",
+  "version": "7.0.6",
+  "description": "An HTTP(s) proxy `http.Agent` implementation for HTTPS",
+  "main": "./dist/index.js",
+  "types": "./dist/index.d.ts",
+  "files": [
+    "dist"
+  ],
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/TooTallNate/proxy-agents.git",
+    "directory": "packages/https-proxy-agent"
+  },
+  "keywords": [
+    "https",
+    "proxy",
+    "endpoint",
+    "agent"
+  ],
+  "author": "Nathan Rajlich <nathan@tootallnate.net> (http://n8.io/)",
+  "license": "MIT",
+  "dependencies": {
+    "agent-base": "^7.1.2",
+    "debug": "4"
+  },
+  "devDependencies": {
+    "@types/async-retry": "^1.4.5",
+    "@types/debug": "4",
+    "@types/jest": "^29.5.1",
+    "@types/node": "^14.18.45",
+    "async-listen": "^3.0.0",
+    "async-retry": "^1.3.3",
+    "jest": "^29.5.0",
+    "ts-jest": "^29.1.0",
+    "typescript": "^5.0.4",
+    "proxy": "2.2.0",
+    "tsconfig": "0.0.0"
+  },
+  "engines": {
+    "node": ">= 14"
+  },
+  "scripts": {
+    "build": "tsc",
+    "test": "jest --env node --verbose --bail test/test.ts",
+    "test-e2e": "jest --env node --verbose --bail test/e2e.test.ts",
+    "lint": "eslint --ext .ts",
+    "pack": "node ../../scripts/pack.mjs"
+  }
+}