Combat: MC-4 combo-chain melee as the primary verb (DR-030)

Melee combo (left-click / pad-West) becomes the player's primary verb; the ranged projectile is demoted to right-click / pad-left-trigger. Predicted, owner-replicated combo Step (path-dependent -> [GhostField] anchor + absolute-write idempotency, NOT derived like the dash), server-only cleave mirroring ProjectileDamageSystem (SourceTick-stamped DamageEvent + KnockbackState), dash-cancellable movement-commit, 9 live TuningConfig knobs, and swing juice scaling with the combo step. The MC-6 archetype byte is deferred (the melee is its own verb). See DR-030.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Assets/_Project/Scripts/Simulation/Player/PlayerInput.cs

@@ -25,6 +25,10 @@ namespace ProjectM.Simulation
         /// so one press dashes exactly once; read by the predicted DashSystem (MC-1).</summary>
         [GhostField] public InputEvent Dash;
 
+        /// <summary>Melee combo attack (MC-4) - the player's PRIMARY verb. InputEvent twin of Fire/Dash: one press =
+        /// one swing attempt across the frame->tick->rollback boundary; read by the predicted MeleeComboSystem.</summary>
+        [GhostField] public InputEvent Attack;
+
         /// <summary>Active input scheme this tick (<see cref="InputSchemeId"/>: 0 = mouse/keyboard, 1 = gamepad).
         /// The server reads it so the auto-target assist applies only to gamepad shots; precise mouse aim is left
         /// exact. A byte (not an enum): it is compared inside the Burst-compiled <c>AbilityFireSystem</c>.</summary>
@@ -35,7 +39,7 @@ namespace ProjectM.Simulation
             var s = new FixedString512Bytes();
             s.Append(Move.x); s.Append(','); s.Append(Move.y); s.Append(';');
             s.Append(Aim.x); s.Append(','); s.Append(Aim.y); s.Append(';');
-            s.Append(Fire.Count); s.Append(';'); s.Append(Scheme); s.Append(';'); s.Append(Dash.Count);
+            s.Append(Fire.Count); s.Append(';'); s.Append(Scheme); s.Append(';'); s.Append(Dash.Count); s.Append(';'); s.Append(Attack.Count);
             return s;
         }
     }