feat(#140): add PhaseTrackerWidget and PhaseStepButton

unity-client/Assets/Scripts/UI/Battleground/PhaseStepButton.cs

@@ -0,0 +1,31 @@
+using UnityEngine;
+using UnityEngine.UI;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// A single phase pill in the PhaseTrackerWidget strip.
+    /// Changes color, font weight, and scale when activated.
+    /// </summary>
+    public class PhaseStepButton : MonoBehaviour
+    {
+        [SerializeField] private Image      background;
+        [SerializeField] private TMP_Text   label;
+
+        [Header("Colors")]
+        [SerializeField] private Color activeColor   = new Color(1f, 0.85f, 0f);     // amber/yellow
+        [SerializeField] private Color inactiveColor = new Color(0.2f, 0.2f, 0.2f);  // dark grey
+
+        private Vector3 _baseScale;
+
+        private void Awake() => _baseScale = transform.localScale;
+
+        public void SetActive(bool active)
+        {
+            if (background) background.color = active ? activeColor : inactiveColor;
+            if (label)      label.fontStyle   = active ? TMPro.FontStyles.Bold : TMPro.FontStyles.Normal;
+            transform.localScale = active ? _baseScale * 1.1f : _baseScale;
+        }
+    }
+}

unity-client/Assets/Scripts/UI/Battleground/PhaseTrackerWidget.cs

@@ -0,0 +1,80 @@
+using UnityEngine;
+using TMPro;
+
+namespace CommanderAILab.UI
+{
+    /// <summary>
+    /// Horizontal strip of 13 phase/step buttons in the BattlefieldCenter panel.
+    /// Subscribes to GameStateManager.OnPhaseChanged.
+    /// Test without backend: press Space in Play Mode (debug binding below).
+    /// </summary>
+    public class PhaseTrackerWidget : MonoBehaviour
+    {
+        public enum Phase
+        {
+            Untap = 0,
+            Upkeep,
+            Draw,
+            Main1,
+            BeginCombat,
+            DeclareAttackers,
+            DeclareBlockers,
+            FirstStrikeDamage,
+            Damage,
+            EndCombat,
+            Main2,
+            EndStep,
+            Cleanup
+        }
+
+        [SerializeField] private PhaseStepButton[] stepButtons;    // 13 buttons, one per Phase
+        [SerializeField] private TMP_Text          activePlayerLabel;
+        [SerializeField] private TMP_Text          turnNumberLabel;
+
+        private Phase _currentPhase;
+
+        // ── Lifecycle ───────────────────────────────────────────
+        private void Start()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnPhaseChanged += SetPhase;
+
+            SetPhase(Phase.Untap, 0, 1);
+        }
+
+        private void OnDestroy()
+        {
+            if (GameStateManager.Instance != null)
+                GameStateManager.Instance.OnPhaseChanged -= SetPhase;
+        }
+
+        // ── Public API ─────────────────────────────────────────
+        public void SetPhase(Phase phase, int seatIndex, int turnNumber)
+        {
+            _currentPhase = phase;
+
+            for (int i = 0; i < stepButtons.Length; i++)
+                stepButtons[i]?.SetActive(i == (int)phase);
+
+            if (activePlayerLabel)
+                activePlayerLabel.text = seatIndex == 0 ? "Your Turn" : $"Seat {seatIndex}'s Turn";
+
+            if (turnNumberLabel)
+                turnNumberLabel.text = $"Turn {turnNumber}";
+        }
+
+        public Phase CurrentPhase => _currentPhase;
+
+        // ── Debug (editor only) ──────────────────────────────────
+#if UNITY_EDITOR
+        private void Update()
+        {
+            if (Input.GetKeyDown(KeyCode.Space))
+            {
+                int next = ((int)_currentPhase + 1) % System.Enum.GetValues(typeof(Phase)).Length;
+                SetPhase((Phase)next, 0, GameStateManager.Instance?.TurnNumber ?? 1);
+            }
+        }
+#endif
+    }
+}