Add player names: settings persistence, replication, screen-space nameplates

- GameSettings: playerName field persisted in Settings.json
- NetworkPlayerSetup: owner-written DisplayName NetworkVariable
  (seeded from settings on spawn, sanitized/truncated, live rename push)
- PlayerNameField: binds the session panel name input to settings
- PlayerNameplates: screen-space overlay labels above players with
  distance-based font scaling (clamped min/max), pooling, FP self-hide

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/Scripts/Network/UI/PlayerNameField.cs

@@ -0,0 +1,44 @@
+using TMPro;
+using UnityEngine;
+
+/// <summary>
+/// Binds the session panel's player-name input to the persisted name (GameSettings/Settings.json).
+/// Seeds the field on enable, saves on end-edit, and pushes a live rename to the already-spawned local
+/// avatar (the Esc overlay keeps the panel reachable while connected); fresh spawns read GameSettings
+/// themselves in <see cref="NetworkPlayerSetup.OnNetworkSpawn"/>.
+/// </summary>
+[DisallowMultipleComponent]
+public class PlayerNameField : MonoBehaviour
+{
+    [Tooltip("Name input. Empty = the first TMP_InputField below this object.")]
+    [SerializeField] private TMP_InputField input;
+
+    private void Awake()
+    {
+        if (!input) input = GetComponentInChildren<TMP_InputField>(true);
+    }
+
+    private void OnEnable()
+    {
+        if (!input) return;
+        input.SetTextWithoutNotify(GameSettings.PlayerName);
+        input.onEndEdit.AddListener(OnEndEdit);
+    }
+
+    private void OnDisable()
+    {
+        if (input) input.onEndEdit.RemoveListener(OnEndEdit);
+    }
+
+    private void OnEndEdit(string value)
+    {
+        GameSettings.PlayerName = value;
+
+        var avatars = NetworkPlayerSetup.Active;
+        for (int i = 0; i < avatars.Count; i++)
+        {
+            var avatar = avatars[i];
+            if (avatar && avatar.IsOwner) avatar.PublishDisplayName(value);
+        }
+    }
+}