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/@parcel/watcher/src/watchman/WatchmanBackend.hh

@@ -0,0 +1,35 @@
+#ifndef WATCHMAN_H
+#define WATCHMAN_H
+
+#include "../Backend.hh"
+#include "./BSER.hh"
+#include "../Signal.hh"
+#include "./IPC.hh"
+
+class WatchmanBackend : public Backend {
+public:
+  static bool checkAvailable();
+  void start() override;
+  WatchmanBackend() : mStopped(false) {};
+  ~WatchmanBackend();
+  void writeSnapshot(WatcherRef watcher, std::string *snapshotPath) override;
+  void getEventsSince(WatcherRef watcher, std::string *snapshotPath) override;
+  void subscribe(WatcherRef watcher) override;
+  void unsubscribe(WatcherRef watcher) override;
+private:
+  std::unique_ptr<IPC> mIPC;
+  Signal mRequestSignal;
+  Signal mResponseSignal;
+  BSER::Object mResponse;
+  std::string mError;
+  std::unordered_map<std::string, WatcherRef> mSubscriptions;
+  bool mStopped;
+  Signal mEndedSignal;
+
+  std::string clock(WatcherRef watcher);
+  void watchmanWatch(std::string dir);
+  BSER::Object watchmanRequest(BSER cmd);
+  void handleSubscription(BSER::Object obj);
+};
+
+#endif