First pass at full refactor to 2.0 design

Restructures the game around the cyclical run loop from Game Design Doc V2:
5 waves = a cycle, 3 cycles = a phase, each phase ends in a boss.

- New TD.Gameplay.Waves: WaveGroup / PhaseDefinition / RunDefinition author the
  run as draggable weighted pools; RunState owns phase/cycle position, the drawn
  wave slots, and the per-slot enemy buff sets. WaveManager's flat wave array is
  gone -- it now only runs the encounter RunState points at.
- New TD.Gameplay.EnemyUpgrades: the post-wave enemy-buff vote, with public
  live-replicated ballots so the HUD can show who voted for what.
- Inter-wave flow is now strictly sequential: draft -> vote -> build, each stage
  ending early once every player has acted.
- Enemy abilities inverted from per-instance random rolls to deterministic,
  stacking per-wave-slot sets. Six cards ship: Split (reworked), Flight, Blink,
  No Bounty, Gold Theft, Double Up.
- Tower upgrades are a two-step tree: a draft pick unlocks a node, gold converts
  an already-placed tower in place.
- Boss encounters flag their enemies and drive a boss HP bar.
- Player cap reduced to 3 via MatchRules.MaxPlayers.
- GoldConfig is now keyed by global encounter number rather than wave index.

Compiles clean; NOT yet verified in-engine. Editor wiring still required --
see Docs/2.0_Setup_Checklist.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Assets/_Project/Scripts/Editor/Gameplay/RunDefinitionEditor.cs

@@ -0,0 +1,69 @@
+// Assets/_Project/Scripts/Editor/Gameplay/RunDefinitionEditor.cs
+using UnityEditor;
+using UnityEngine;
+using TD.Gameplay.Waves;
+
+namespace TD.Editor.Gameplay
+{
+    /// <summary>
+    /// Inspector for <see cref="RunDefinition"/>. Draws the normal fields, then a live
+    /// validation panel reporting whether the authored pools can actually produce a run.
+    /// </summary>
+    /// <remarks>
+    /// The check that matters here is the distinct-enemy-type one: because enemy upgrades are
+    /// keyed to a wave slot, a phase must be able to fill its cycle with waves that use different
+    /// enemies. A pool can look healthy (plenty of entries) and still fail that. Reporting it in
+    /// the inspector turns a startup error into something a designer sees while authoring.
+    /// </remarks>
+    [CustomEditor(typeof(RunDefinition))]
+    public class RunDefinitionEditor : UnityEditor.Editor
+    {
+        public override void OnInspectorGUI()
+        {
+            DrawDefaultInspector();
+
+            var run = (RunDefinition)target;
+
+            EditorGUILayout.Space();
+            EditorGUILayout.LabelField("Validation", EditorStyles.boldLabel);
+
+            bool ok = run.Validate(out string report);
+            EditorGUILayout.HelpBox(report, ok ? MessageType.Info : MessageType.Error);
+
+            // Per-phase capacity readout — the fastest way to see how much headroom a pool has
+            // before the distinct-type requirement starts biting.
+            if (run.Phases != null)
+            {
+                EditorGUILayout.Space();
+                EditorGUILayout.LabelField("Phase capacity", EditorStyles.boldLabel);
+
+                for (int i = 0; i < run.Phases.Length; i++)
+                {
+                    var phase = run.Phases[i];
+                    if (phase == null)
+                    {
+                        EditorGUILayout.LabelField($"Phase {i + 1}", "— empty —");
+                        continue;
+                    }
+
+                    int distinct = phase.CountDistinctEnemyTypes();
+                    string value = $"{distinct} distinct enemy type(s) / {run.WavesPerCycle} needed";
+                    var style = new GUIStyle(EditorStyles.label)
+                    {
+                        normal = { textColor = distinct >= run.WavesPerCycle
+                            ? EditorStyles.label.normal.textColor
+                            : new Color(0.9f, 0.4f, 0.3f) }
+                    };
+                    EditorGUILayout.LabelField(phase.Label, value, style);
+                }
+            }
+
+            EditorGUILayout.Space();
+            if (GUILayout.Button("Rebuild Wave Index"))
+            {
+                run.RebuildIndex();
+                Debug.Log($"[RunDefinition] Rebuilt wave index: {run.WaveCount} distinct wave(s).");
+            }
+        }
+    }
+}