Refactor scripts: dedup remainder, remove dead code, perf hardening

Iteration 4 over Assets/Scripts (no component/file splits, no Unity assets touched):

Dedup:
- Route inline cursor-release, material guards, Ctrl-held and undo/redo
  input through existing InputUtil / SetMatFloat helpers
- Add ungated InputUtil.KeyPressedThisFrame; GameplayKeyPressed builds on it
- Unify FindDeep/FindDeepChild into GeometryUtil.FindDeep

Dead code / stale docs:
- Remove unused code-gen bake path (HsvColorPicker.Build, PaintHud factory)
- Drop unreferenced symbols (SubPhaseChanged event, LocalPhaseDuration,
  IsLocalSceneMain, MouseSensitivity.Changed, IsPaused, InSession,
  NetworkControlled, PreviousPose, JointCount, voxel-count accessors)
- Fix incorrect PlayerRole / PaintHud / Pick / PlayerPose docs

Perf / robustness (behaviour-neutral):
- ConcealmentMeter.Evaluate: reuse vertex/topology buffers, two-pointer
  crossing count
- BuildMeshCaches: alloc-free vertex copy, cached topology/UVs
- Guard all PlayerPaintSync LogSync sites behind logSync
- Cache LocalViewerIsHunter / controller / CanShoot / TypingGuard lookups;
  dedup LocalIsHunter with MatchHud
- Change-guard RefreshEmissionColor and HeroCutout.Disarm
- Cache scene/countdown string comparisons per frame
- Grow NonAlloc buffers and log-once on saturation

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

Assets/Scripts/StartMatchTrigger.cs

@@ -25,8 +25,9 @@ using UnityEngine;
 public class StartMatchTrigger : MonoBehaviour
 {
     private Collider _collider;
-    private readonly Collider[] _overlap = new Collider[16];
+    private readonly Collider[] _overlap = new Collider[32];
     private bool _started;
+    private bool _overlapSaturated; // log-once: a full buffer could silently drop the authority's avatar
 
     private void Awake() => _collider = GetComponent<Collider>();
 
@@ -40,6 +41,11 @@ public class StartMatchTrigger : MonoBehaviour
         if (!match || match.Phase != MatchManager.MatchPhase.Lobby) return;
 
         int count = OverlapTrigger();
+        if (count == _overlap.Length && !_overlapSaturated)
+        {
+            _overlapSaturated = true;
+            Debug.LogWarning($"StartMatchTrigger: overlap buffer saturated ({count}); the authority avatar may be missed.", this);
+        }
         for (int i = 0; i < count; i++)
         {
             var netObj = _overlap[i].GetComponentInParent<NetworkObject>();