Initial commit: Theriapolis baseline at port/godot branch point

Captures the pre-Godot-port state of the codebase. This is the rollback
anchor for the Godot port (M0 of theriapolis-rpg-implementation-plan-godot-port.md).
All Phase 0 through Phase 6.5 work is included; Phase 7 is in flight.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Theriapolis.Core/Rules/Combat/NpcInstantiator.cs

@@ -0,0 +1,36 @@
+using Theriapolis.Core.Data;
+using Theriapolis.Core.Tactical;
+
+namespace Theriapolis.Core.Rules.Combat;
+
+/// <summary>
+/// Maps a <see cref="TacticalSpawn"/> + chunk's <see cref="TacticalChunk.DangerZone"/>
+/// to the actual <see cref="NpcTemplateDef"/> that should spawn there.
+/// Lookup table lives in <c>npc_templates.json</c>'s
+/// <c>spawn_kind_to_template_by_zone</c> map (loaded into
+/// <see cref="NpcTemplateContent.SpawnKindToTemplateByZone"/>).
+///
+/// Returns null when no template is configured for the spawn kind/zone (the
+/// caller should skip that spawn — chunk is silently denser, that's OK).
+/// </summary>
+public static class NpcInstantiator
+{
+    public static NpcTemplateDef? PickTemplate(
+        SpawnKind kind,
+        int dangerZone,
+        NpcTemplateContent content)
+    {
+        if (kind == SpawnKind.None) return null;
+        string kindKey = kind.ToString();
+        if (!content.SpawnKindToTemplateByZone.TryGetValue(kindKey, out var byZone))
+            return null;
+        if (byZone.Length == 0) return null;
+        // Clamp the zone index to the table's length.
+        int zoneIdx = System.Math.Clamp(dangerZone, 0, byZone.Length - 1);
+        string templateId = byZone[zoneIdx];
+        foreach (var t in content.Templates)
+            if (string.Equals(t.Id, templateId, System.StringComparison.OrdinalIgnoreCase))
+                return t;
+        return null;
+    }
+}