Fix: Use force_refresh=True in unity_instances resource for cache consistency

The unity_instances resource was using force_refresh=False, which returned
cached instances (5-second cache). This caused a mismatch with set_active_instance
which uses force_refresh=True, leading to instances being shown in the resource
that no longer existed when trying to set them as active.

By changing to force_refresh=True, the resource now always shows current instances
that match what set_active_instance sees, fixing the instance switching issue.

Author: dsarno

Server/resources/unity_instances.py

@@ -34,7 +34,7 @@ async def unity_instances(ctx: Context) -> dict[str, Any]:
 
     try:
         pool = get_unity_connection_pool()
-        instances = pool.discover_all_instances(force_refresh=False)
+        instances = pool.discover_all_instances(force_refresh=True)
 
         # Check for duplicate project names
         name_counts = {}