UITK HUD rework + build palette (click-to-place ghost)

Rebuild the in-game HUD on UI Toolkit (HudUi/HudSystem, Aether palette) consistent with the menu; build-palette bar (BuildPaletteState) drives cursor->cell ground-ghost preview (green/red via BuildPreviewMath), left-click place / right-click cancel / rotate; fire suppressed in build mode; combat juice restyle. +4 BuildPreviewMath EditMode tests.

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

Assets/_Project/Scripts/Client/Presentation/CombatFeedbackSystem.cs

@@ -343,6 +343,7 @@ namespace ProjectM.Client
             tm.anchor = TextAnchor.MiddleCenter;
             tm.alignment = TextAlignment.Center;
             tm.color = Color.white;
+            tm.fontStyle = FontStyle.Bold;
             go.SetActive(false);
             return new FloatingNumber { Tm = tm, Tr = go.transform, Active = false };
         }
@@ -358,7 +359,7 @@ namespace ProjectM.Client
             fn.Age = 0f;
             fn.Life = 0.7f;
             fn.Tm.text = Mathf.Max(1, Mathf.RoundToInt(amount)).ToString();
-            fn.BaseColor = isLocalPlayer ? new Color(1f, 0.32f, 0.26f) : new Color(1f, 0.92f, 0.45f);
+            fn.BaseColor = isLocalPlayer ? new Color(1f, 0.5f, 0.22f) : new Color(0.45f, 0.92f, 1f); // Blight orange (hurt) / Aether cyan (you hit)
             fn.Tm.color = fn.BaseColor;
             fn.Tr.position = worldPos + Vector3.up * 1.4f + new Vector3(UnityEngine.Random.Range(-0.25f, 0.25f), 0f, 0f);
             fn.Vel = new Vector3(0f, 2.2f, 0f);
@@ -478,7 +479,7 @@ namespace ProjectM.Client
         static void PlayClip(AudioClip clip, Vector3 pos, float vol)
         {
             if (clip == null) return;
-            AudioSource.PlayClipAtPoint(clip, pos, vol);
+            AudioSource.PlayClipAtPoint(clip, pos, vol * GameVolume.Sfx);
         }
     }
 }