Add lobby/match-start matchmaking flow with additive scene management

Replace the connection-approval role selection with a server-authoritative
match flow built on NGO additive scene management:

- Scenes: Main is the persistent foundation (NetworkManager, GameModeManager,
  cameras, HUD); Lobby and Test Map load/unload additively. Add Lobby + Test Map
  to the build settings; remove the obsolete SampleScene.
- MatchManager (plain MonoBehaviour singleton): loads Lobby on server start,
  StartMatchTrigger lets the host start the match, rolls one random Hunter (rest
  Hider), swaps Lobby -> Test Map (strictly serialized per NGO), respawns each
  player as its role variant. Forces additive client sync mode so clients keep
  Main instead of single-loading it (fixes "Destination scene is not valid").
- Server-driven spawning: null out NetworkConfig.PlayerPrefab at runtime to
  disable auto-spawn, then spawn players after the lobby floor exists (fixes
  falling through the floor) with double-spawn and transition guards.
- StartMatchTrigger: server-gated OnTriggerEnter, only the host's own player
  starts the match.
- NetworkBootstrap: drop role selection / connection approval; everyone spawns
  as the neutral Player prefab. Host/Client/Server/Shutdown buttons stay.
- NetworkPlayerSetup.ScopedModes flag (baked on Hunter/Hider prefabs): lobby
  avatar gets the full mode set, match variants get the role-scoped set.
- GameModeManager.BindLocalPlayer reads ScopedModes and rebinds the painter
  unconditionally (fixes stale painter binding on respawn -> brush painting in
  every mode).
- MeshPainter.PaintingEnabled defaults to false (unbound/pre-spawn/remote never
  paints); PaintHud visibility now also gates on a bound painter (fixes the HUD
  showing at startup before any avatar exists).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Scripts/NetworkBootstrap.cs

@@ -5,12 +5,12 @@ using UnityEngine.InputSystem;
 #endif
 
 /// <summary>
-/// Dev-only connection harness for local multiplayer testing across the junction-mirror clones:
-/// pick a role (Hunter/Hider) in the panel, then one instance clicks Host and the others click
-/// Client (loopback 127.0.0.1 via the configured UnityTransport). The chosen role rides along as the
-/// connection-approval payload, so the server spawns that role's prefab variant for the connection.
-/// Hotkeys: H = Host, C = Client, J = Server, K = Shutdown. Purely a testing scaffold - replace with
-/// real lobby/menu UI later. Attach to the same GameObject as the NetworkManager.
+/// Dev-only connection harness for local multiplayer testing across the junction-mirror clones: one
+/// instance clicks Host and the others click Client (loopback 127.0.0.1 via the configured
+/// UnityTransport). Everyone spawns as the neutral Player prefab into the Lobby; roles (Hunter/Hider)
+/// are rolled and applied by <see cref="MatchManager"/> when the match starts, not here. Hotkeys:
+/// H = Host, C = Client, J = Server, K = Shutdown. Purely a testing scaffold - replace with real
+/// lobby/menu UI later. Attach to the same GameObject as the NetworkManager.
 /// </summary>
 [RequireComponent(typeof(NetworkManager))]
 [DisallowMultipleComponent]
@@ -22,51 +22,9 @@ public class NetworkBootstrap : MonoBehaviour
     [Tooltip("Allow the H/C/J/K keyboard shortcuts.")]
     public bool enableHotkeys = true;
 
-    [Header("Role prefabs")]
-    [Tooltip("Prefab spawned for a connection that picked Hunter. Must be registered as a network prefab.")]
-    [SerializeField] private GameObject hunterPrefab;
-
-    [Tooltip("Prefab spawned for a connection that picked Hider. Must be registered as a network prefab.")]
-    [SerializeField] private GameObject hiderPrefab;
-
-    [Tooltip("Role this instance connects as. Toggle it in the dev panel before hosting/joining.")]
-    [SerializeField] private PlayerRole selectedRole = PlayerRole.Hider;
-
     private NetworkManager _net;
 
-    private void Awake()
-    {
-        _net = GetComponent<NetworkManager>();
-
-        // Per-connection prefab selection needs connection approval: the callback maps the role byte
-        // the joiner sent to the matching prefab hash. Enabled here so the scene asset needn't carry it.
-        _net.NetworkConfig.ConnectionApproval = true;
-        _net.ConnectionApprovalCallback = ApprovalCheck;
-    }
-
-    /// <summary>Stamps the chosen role into the connection payload, then starts the given mode.
-    /// StartHost runs approval on its own client too, so the host's role is read from this same payload.</summary>
-    private void StartAs(System.Func<bool> start)
-    {
-        _net.NetworkConfig.ConnectionData = new[] { (byte)selectedRole };
-        start();
-    }
-
-    private void ApprovalCheck(NetworkManager.ConnectionApprovalRequest request,
-                               NetworkManager.ConnectionApprovalResponse response)
-    {
-        PlayerRole role = (request.Payload != null && request.Payload.Length > 0)
-            ? (PlayerRole)request.Payload[0]
-            : PlayerRole.Hider;
-
-        GameObject prefab = role == PlayerRole.Hunter ? hunterPrefab : hiderPrefab;
-        var netObj = prefab ? prefab.GetComponent<NetworkObject>() : null;
-
-        response.Approved = true;
-        response.CreatePlayerObject = true;
-        // Null prefab/ref falls back to the NetworkManager's default PlayerPrefab.
-        if (netObj) response.PlayerPrefabHash = netObj.PrefabIdHash;
-    }
+    private void Awake() => _net = GetComponent<NetworkManager>();
 
     private void Update()
     {
@@ -76,9 +34,9 @@ public class NetworkBootstrap : MonoBehaviour
         if (kb == null || _net == null) return;
         if (!_net.IsListening)
         {
-            if (kb.hKey.wasPressedThisFrame) StartAs(_net.StartHost);
-            else if (kb.cKey.wasPressedThisFrame) StartAs(_net.StartClient);
-            else if (kb.jKey.wasPressedThisFrame) StartAs(_net.StartServer);
+            if (kb.hKey.wasPressedThisFrame) _net.StartHost();
+            else if (kb.cKey.wasPressedThisFrame) _net.StartClient();
+            else if (kb.jKey.wasPressedThisFrame) _net.StartServer();
         }
         else if (kb.kKey.wasPressedThisFrame)
         {
@@ -91,25 +49,18 @@ public class NetworkBootstrap : MonoBehaviour
     {
         if (!showGui || _net == null) return;
 
-        GUILayout.BeginArea(new Rect(10, 10, 220, 200), GUI.skin.box);
+        GUILayout.BeginArea(new Rect(10, 10, 220, 160), GUI.skin.box);
         if (!_net.IsListening)
         {
             GUILayout.Label("Netcode (dev)");
-
-            GUILayout.BeginHorizontal();
-            GUILayout.Label("Role:", GUILayout.Width(38));
-            if (GUILayout.Toggle(selectedRole == PlayerRole.Hider, "Hider", GUI.skin.button)) selectedRole = PlayerRole.Hider;
-            if (GUILayout.Toggle(selectedRole == PlayerRole.Hunter, "Hunter", GUI.skin.button)) selectedRole = PlayerRole.Hunter;
-            GUILayout.EndHorizontal();
-
-            if (GUILayout.Button("Host (H)")) StartAs(_net.StartHost);
-            if (GUILayout.Button("Client (C)")) StartAs(_net.StartClient);
-            if (GUILayout.Button("Server (J)")) StartAs(_net.StartServer);
+            if (GUILayout.Button("Host (H)")) _net.StartHost();
+            if (GUILayout.Button("Client (C)")) _net.StartClient();
+            if (GUILayout.Button("Server (J)")) _net.StartServer();
         }
         else
         {
             string role = _net.IsHost ? "Host" : _net.IsServer ? "Server" : "Client";
-            GUILayout.Label($"Role: {role} ({selectedRole})");
+            GUILayout.Label($"Role: {role}");
             GUILayout.Label($"ClientId: {_net.LocalClientId}");
             GUILayout.Label($"Clients: {(_net.IsServer ? _net.ConnectedClients.Count : (_net.IsConnectedClient ? 1 : 0))}");
             if (GUILayout.Button("Shutdown (K)")) _net.Shutdown();