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/PaintHud.cs

@@ -11,10 +11,10 @@ using UnityEngine.InputSystem.UI;
 /// <see cref="PaintMode"/> (follows the manager's ModeChanged) and binds its widgets directly to the
 /// live <see cref="MeshPainter"/> fields, so edits apply immediately.
 ///
-/// The layout (independently draggable sub-panels per channel + a global brush card) comes from an
-/// authored prefab (<see cref="layoutPrefab"/>) or is generated in code as the fallback. Either way
-/// the BINDINGS live in code and are (re)applied at runtime by <see cref="WirePanel"/> against the
-/// same stable widget names - a prefab stores only the visual layout, never behaviour.
+/// The layout (independently draggable sub-panels per channel + a global brush card) comes from the
+/// authored prefab (<see cref="layoutPrefab"/>). The BINDINGS live in code and are (re)applied at
+/// runtime by <see cref="WirePanel"/> against stable widget names - the prefab stores only the
+/// visual layout, never behaviour.
 /// </summary>
 [DisallowMultipleComponent]
 public partial class PaintHud : MonoBehaviour
@@ -25,10 +25,10 @@ public partial class PaintHud : MonoBehaviour
     [Tooltip("Painter the HUD edits. Empty = the manager's painter, else found automatically.")]
     public MeshPainter painter;
 
-    [Tooltip("Authored panel layout. If set it is instantiated and bound; empty = build the panel in code.")]
+    [Tooltip("Authored panel layout. Instantiated and bound at startup.")]
     public GameObject layoutPrefab;
 
-    // Stable widget names shared by the code-gen builder, the baked prefab and the binder.
+    // Stable widget names shared by the baked prefab and the binder.
     private const string PanelGeneral = "Panel_General";
     private const string PanelSpray = "Panel_Spray";
     private const string PanelAlbedo = "Panel_Albedo";
@@ -408,13 +408,13 @@ public partial class PaintHud : MonoBehaviour
     /// </summary>
     private void WireMaskSelector(Transform panel)
     {
-        var selector = FindDeep(panel, MaskSelector);
+        var selector = GeometryUtil.FindDeep(panel, MaskSelector);
         if (!selector) return;
         var masks = painter ? painter.brushMasks : null;
 
         for (int i = 0; ; i++)
         {
-            var swatch = FindDeep(selector, MaskSwatchPrefix + i);
+            var swatch = GeometryUtil.FindDeep(selector, MaskSwatchPrefix + i);
             if (!swatch) break;
 
             bool has = masks != null && i < masks.Count && masks[i];
@@ -445,12 +445,12 @@ public partial class PaintHud : MonoBehaviour
     private void RefreshMaskHighlights()
     {
         if (!_panel || !painter) return;
-        var selector = FindDeep(_panel.transform, MaskSelector);
+        var selector = GeometryUtil.FindDeep(_panel.transform, MaskSelector);
         if (!selector) return;
 
         for (int i = 0; ; i++)
         {
-            var swatch = FindDeep(selector, MaskSwatchPrefix + i);
+            var swatch = GeometryUtil.FindDeep(selector, MaskSwatchPrefix + i);
             if (!swatch) break;
             var frame = swatch.GetComponent<Image>();
             if (frame) frame.color = i == painter.activeBrushIndex ? MaskFrameSelected : MaskFrameUnselected;
@@ -477,7 +477,7 @@ public partial class PaintHud : MonoBehaviour
     /// </summary>
     private void MakeDraggable(Transform root, string panelName)
     {
-        var panel = FindDeep(root, panelName) as RectTransform;
+        var panel = GeometryUtil.FindDeep(root, panelName) as RectTransform;
         if (!panel) return;
         var drag = panel.GetComponent<DraggablePanel>();
         if (!drag) drag = panel.gameObject.AddComponent<DraggablePanel>();
@@ -507,7 +507,7 @@ public partial class PaintHud : MonoBehaviour
     /// </summary>
     private static void WirePanelFade(Transform root, string panelName, string toggleName)
     {
-        var panel = FindDeep(root, panelName);
+        var panel = GeometryUtil.FindDeep(root, panelName);
         if (!panel) return;
         var group = panel.GetComponent<CanvasGroup>();
         if (!group) group = panel.gameObject.AddComponent<CanvasGroup>();
@@ -522,7 +522,7 @@ public partial class PaintHud : MonoBehaviour
     /// <summary>Finds a slider cell by name and the Slider inside it (null when either is missing).</summary>
     private static Slider FindSlider(Transform panel, string name, out Transform cell)
     {
-        cell = FindDeep(panel, name);
+        cell = GeometryUtil.FindDeep(panel, name);
         return cell ? cell.GetComponentInChildren<Slider>() : null;
     }
 
@@ -560,52 +560,10 @@ public partial class PaintHud : MonoBehaviour
 
     private static T Find<T>(Transform panel, string name) where T : Component
     {
-        var child = FindDeep(panel, name);
+        var child = GeometryUtil.FindDeep(panel, name);
         return child ? child.GetComponent<T>() : null;
     }
 
-    /// <summary>Depth-first search by name (widgets now live nested inside per-channel sub-panels).</summary>
-    private static Transform FindDeep(Transform root, string name)
-    {
-        if (root.name == name) return root;
-        for (int i = 0; i < root.childCount; i++)
-        {
-            var found = FindDeep(root.GetChild(i), name);
-            if (found) return found;
-        }
-        return null;
-    }
-
-    // --- Static UI factory (shared with HsvColorPicker) ---
-
-    public static RectTransform NewRect(string name, Transform parent)
-    {
-        var go = new GameObject(name, typeof(RectTransform));
-        go.transform.SetParent(parent, false);
-        return (RectTransform)go.transform;
-    }
-
-    public static Image AddImage(GameObject go, Color color)
-    {
-        var img = go.AddComponent<Image>();
-        img.color = color;
-        return img;
-    }
-
-    /// <summary>Adds a full-rect, non-raycasting overlay image (sprite assigned by the caller).</summary>
-    public static Image AddOverlay(RectTransform parent, string name)
-    {
-        var rt = NewRect(name, parent);
-        rt.anchorMin = Vector2.zero;
-        rt.anchorMax = Vector2.one;
-        rt.offsetMin = Vector2.zero;
-        rt.offsetMax = Vector2.zero;
-        var img = rt.gameObject.AddComponent<Image>();
-        img.type = Image.Type.Simple;
-        img.raycastTarget = false;
-        return img;
-    }
-
     // Cached gradient sprites for the colour picker.
     private static Sprite _satSprite, _valSprite, _hueSprite;