Built player throws NullReferenceException per TextMeshPro component when TMP Essential Resources are not imported

Steps to reproduce:
1. Create a new project using the Universal 3D template
2. Install Multiplayer Widgets and Netcode for GameObjects packages via Package Manager window (com.unity.multiplayer.widgets, com.unity.netcode.gameobjects)
3. Do not import TMP Essential Resources (skip Window > TextMeshPro > Import TMP Essential Resources; dismiss the dialog if it appears) and verify no Assets/TextMesh Pro folder exists
4. In Hierarchy, add a GameObject with the NetworkManager component, then drag the "Create Session" prefab from Packages > Multiplayer Widgets > Assets/Prefabs/Create into the Hierarchy window
5. Clean Console window
6. Build the project (File > Build Profiles > Build)
7. Run the built player and observe its log (~/Library/Logs/<Company>/<Product>/Player.log, or launch it with -logFile)

Actual results: the build succeeds with 0 errors, then the player logs 9 unhandled NullReferenceExceptions from TMPro.TextMeshProUGUI.Awake() and displays no text

Expected results: either the widgets carry their TextMeshPro requirement, or the Editor warns at authoring or build time that TMP Essential Resources are required

Reproducible with versions: 1.0.5 (6000.0.84f1, 6000.3.24f1, 6000.5.11f1, 6000.6.1f1, 6000.7.0a6)

Tested on (OS): macOS 26.6.1 (Apple silicon)

NullReferenceException: Object reference not set to an instance of an object
  at TMPro.TMP_Settings.get_defaultFontAsset () [0x00005] in <da99cc33a6de47548a61152b49e6d66a>:0 
  at TMPro.TextMeshProUGUI.LoadFontAsset () [0x0000e] in <da99cc33a6de47548a61152b49e6d66a>:0 
  at TMPro.TextMeshProUGUI.Awake () [0x000b6] in <da99cc33a6de47548a61152b49e6d66a>:0 
UnityEngine.StackTraceUtility:ExtractStringFromExceptionInternal(Object, String&, String&)