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/Character/Allegiance.cs

@@ -0,0 +1,29 @@
+namespace Theriapolis.Core.Rules.Character;
+
+/// <summary>
+/// Whose side an actor is on at the moment. Drives encounter-trigger logic:
+/// hostile → auto-trigger combat on LOS; friendly/neutral → "[F] Talk to ..."
+/// prompt. Phase 5 sets this from <see cref="Data.NpcTemplateDef.DefaultAllegiance"/>;
+/// faction logic in Phase 6 may mutate it at runtime.
+/// </summary>
+public enum Allegiance : byte
+{
+    Player   = 0,
+    Allied   = 1,
+    Neutral  = 2,
+    Friendly = 3,
+    Hostile  = 4,
+}
+
+public static class AllegianceExtensions
+{
+    public static Allegiance FromJson(string raw) => raw.ToLowerInvariant() switch
+    {
+        "player"   => Allegiance.Player,
+        "allied"   => Allegiance.Allied,
+        "neutral"  => Allegiance.Neutral,
+        "friendly" => Allegiance.Friendly,
+        "hostile"  => Allegiance.Hostile,
+        _ => throw new ArgumentException($"Unknown allegiance: '{raw}'"),
+    };
+}