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.Tests/Reputation/FactionOppositionTests.cs

@@ -0,0 +1,110 @@
+using Theriapolis.Core;
+using Theriapolis.Core.Data;
+using Theriapolis.Core.Rules.Reputation;
+using Xunit;
+
+namespace Theriapolis.Tests.Reputation;
+
+/// <summary>
+/// Phase 6 M2 — opposition matrix application.
+///
+/// The plan §I-2 spells out the exact multipliers; this suite verifies
+/// the cascade fires in both directions (gains and losses) and stays
+/// inside the clamp range.
+/// </summary>
+public sealed class FactionOppositionTests
+{
+    private static IReadOnlyDictionary<string, FactionDef> LoadFactions()
+        => new ContentResolver(new ContentLoader(TestHelpers.DataDirectory)).Factions;
+
+    [Fact]
+    public void GainWithInheritors_CascadesIntoOppositionLosses()
+    {
+        var factions = LoadFactions();
+        var standing = new FactionStanding();
+
+        var applied = standing.Apply("inheritors", 10, factions);
+
+        // Per the doc: +10 with Inheritors should yield -5 Enforcers,
+        // -2 Thorn Council, -3 Hybrid Underground, -3 Unsheathed.
+        Assert.Equal( 10, standing.Get("inheritors"));
+        Assert.Equal( -5, standing.Get("covenant_enforcers"));
+        Assert.Equal( -2, standing.Get("thorn_council"));
+        Assert.Equal( -3, standing.Get("hybrid_underground"));
+        Assert.Equal( -3, standing.Get("unsheathed"));
+        Assert.Equal(  0, standing.Get("merchant_guilds"));   // multiplier 0
+
+        // The applied list reports every actually-changed faction.
+        Assert.Contains(applied, t => t.FactionId == "inheritors"        && t.Delta ==  10);
+        Assert.Contains(applied, t => t.FactionId == "covenant_enforcers" && t.Delta == -5);
+    }
+
+    [Fact]
+    public void LossWithInheritors_CascadesIntoOppositionGains()
+    {
+        var factions = LoadFactions();
+        var standing = new FactionStanding();
+        standing.Apply("inheritors", -20, factions);
+
+        // -20 × -0.5 = +10 with Enforcers.
+        Assert.Equal(-20, standing.Get("inheritors"));
+        Assert.Equal( 10, standing.Get("covenant_enforcers"));
+        Assert.Equal(  4, standing.Get("thorn_council"));
+        Assert.Equal(  6, standing.Get("hybrid_underground"));
+        Assert.Equal(  6, standing.Get("unsheathed"));
+    }
+
+    [Fact]
+    public void Standing_IsClampedToRepRange()
+    {
+        var factions = LoadFactions();
+        var standing = new FactionStanding();
+        standing.Apply("inheritors", 200, factions);
+        Assert.Equal(C.REP_MAX, standing.Get("inheritors"));
+        // Cascaded -100 is below the floor — verify clamping.
+        Assert.Equal(C.REP_MIN, standing.Get("covenant_enforcers"));
+    }
+
+    [Fact]
+    public void ZeroDelta_DoesNothing()
+    {
+        var factions = LoadFactions();
+        var standing = new FactionStanding();
+        standing.Set("inheritors", 25);
+        standing.Apply("inheritors", 0, factions);
+        Assert.Equal(25, standing.Get("inheritors"));
+        Assert.Equal( 0, standing.Get("covenant_enforcers"));
+    }
+
+    [Fact]
+    public void UnknownFaction_NoCascade()
+    {
+        var factions = LoadFactions();
+        var standing = new FactionStanding();
+        // No throw; standing accumulates against the unknown id.
+        standing.Apply("not_a_real_faction", 10, factions);
+        Assert.Equal(10, standing.Get("not_a_real_faction"));
+        Assert.Equal( 0, standing.Get("covenant_enforcers"));
+    }
+
+    [Fact]
+    public void SubmitEvent_AppliesFactionAndPersonal()
+    {
+        var factions = LoadFactions();
+        var rep      = new PlayerReputation();
+
+        rep.Submit(new RepEvent
+        {
+            Kind      = RepEventKind.Quest,
+            FactionId = "inheritors",
+            RoleTag   = "test.someone",
+            Magnitude = 10,
+            Note      = "test event",
+        }, factions);
+
+        Assert.Equal(10,  rep.Factions.Get("inheritors"));
+        Assert.Equal(-5,  rep.Factions.Get("covenant_enforcers"));
+        Assert.Equal(10,  rep.PersonalFor("test.someone").Score);
+        Assert.Single(rep.Ledger.Entries);
+    }
+}