NEO-135: apply standing deltas from clamped effective value

Compute newStanding from previousStanding + deltaAmount so stale
out-of-band persisted values match TryGetStanding before mutation.

server/NeonSprawl.Server.Tests/Game/Factions/InMemoryFactionStandingStoreTests.cs

@@ -118,6 +118,22 @@ public sealed class InMemoryFactionStandingStoreTests
         Assert.Equal(0, store.TryGetStanding(PlayerId, GridFactionId).Standing);
     }
 
+    [Fact]
+    public void TryApplyStandingDelta_ShouldApplyToClampedEffectiveStanding_WhenRawStoredValueExceedsMax()
+    {
+        // Arrange
+        var store = CreateStore();
+        store.SeedRawStandingForTests(PlayerId, GridFactionId, 999);
+        Assert.Equal(100, store.TryGetStanding(PlayerId, GridFactionId).Standing);
+        // Act
+        var outcome = store.TryApplyStandingDelta(PlayerId, GridFactionId, -15);
+        // Assert
+        Assert.True(outcome.Success);
+        Assert.Equal(100, outcome.PreviousStanding);
+        Assert.Equal(85, outcome.NewStanding);
+        Assert.Equal(85, store.TryGetStanding(PlayerId, GridFactionId).Standing);
+    }
+
     [Fact]
     public void TryGetStanding_ShouldPreferUnknownFaction_WhenPlayerNotWritableAndFactionUnknown()
     {

server/NeonSprawl.Server/Game/Factions/InMemoryFactionStandingStore.cs

@@ -93,7 +93,7 @@ public sealed class InMemoryFactionStandingStore(
         {
             var raw = standingByKey.GetValueOrDefault(key, 0);
             var previousStanding = FactionStandingIds.ClampStanding(raw, definition);
-            var newStanding = FactionStandingIds.ClampStanding(raw + deltaAmount, definition);
+            var newStanding = FactionStandingIds.ClampStanding(previousStanding + deltaAmount, definition);
             standingByKey[key] = newStanding;
             return new FactionStandingMutationOutcome(true, null, previousStanding, newStanding);
         }

server/NeonSprawl.Server/Game/Factions/PostgresFactionStandingStore.cs

@@ -117,7 +117,7 @@ public sealed class PostgresFactionStandingStore(
         }
 
         var previousStanding = FactionStandingIds.ClampStanding(raw, definition);
-        var newStanding = FactionStandingIds.ClampStanding(raw + deltaAmount, definition);
+        var newStanding = FactionStandingIds.ClampStanding(previousStanding + deltaAmount, definition);
 
         using var upsert = new Npgsql.NpgsqlCommand(
             """