fix: purge collapsed nations from city conflicts

packages/logic/src/war/aftermath.ts

@@ -105,16 +105,22 @@ const applyNationTechGain = <TriggerState extends GeneralTriggerState>(
     nation.meta.tech = round(tech);
 };
 
-const resolveConquerNation = (city: City, attackerNationId: number): number => {
+const resolveConquerNation = (city: City, attackerNationId: number, nations: Nation[]): number => {
     const rawConflict = city.meta[META_CONFLICT];
     if (!rawConflict) {
         return attackerNationId;
     }
     try {
         const parsed = JSON.parse(String(rawConflict)) as Record<string, number>;
+        const activeNationIds = new Set(nations.map((nation) => nation.id));
         const entries = Object.entries(parsed)
             .map(([key, value]) => [Number(key), value] as const)
-            .filter(([key, value]) => Number.isFinite(key) && typeof value === 'number')
+            .filter(
+                ([key, value]) =>
+                    Number.isFinite(key) &&
+                    typeof value === 'number' &&
+                    (key === attackerNationId || activeNationIds.has(key))
+            )
             .sort(([, lhs], [, rhs]) => rhs - lhs);
         if (!entries.length) {
             return attackerNationId;
@@ -183,7 +189,7 @@ const resolveConquerCity = <TriggerState extends GeneralTriggerState>(
     const affectedGenerals = new Set<General<TriggerState>>();
     const affectedNations = new Set<Nation>();
 
-    const conquerNationId = resolveConquerNation(defenderCity, attackerNation.id);
+    const conquerNationId = resolveConquerNation(defenderCity, attackerNation.id, input.nations);
     const attackerLogger = new ActionLogger({
         generalId: attacker.id,
         nationId: attackerNation.id,

packages/logic/test/warAftermath.test.ts

@@ -183,7 +183,7 @@ describe('war aftermath', () => {
         defenderNation.rice = 6000;
         const attackerCity = buildCity(1, 1);
         const defenderCity = buildCity(2, 2);
-        defenderCity.meta.conflict = JSON.stringify({ 1: 100 });
+        defenderCity.meta.conflict = JSON.stringify({ 99: 200, 1: 100 });
         const attacker = buildGeneral(1, 1, 1);
         const defender = buildGeneral(2, 2, 2);
 
@@ -235,6 +235,8 @@ describe('war aftermath', () => {
         expect(attackerNation.rice).toBe(4600);
         expect(defender.experience).toBe(90);
         expect(defender.dedication).toBe(50);
+        // Removed nations can remain in old persisted conflict metadata. They
+        // must never receive ownership during a later conquest.
         expect(defenderCity.nationId).toBe(attackerNation.id);
         expect(defenderCity.meta.conflict).toBe('{}');
     });