feat(loot): add item, loot table, and combat reward entities

Declares every new TypeORM entity Slice 0.4 needs (ItemDefinition,
CharacterItem, LootTable, LootTableEntry, CombatReward, CombatRewardItem)
plus the ItemType/EquipmentSlot/ItemRarity enums, and adds the two columns
existing entities gain: Character.silver and MonsterDefinition.lootTableId.
No migration SQL or service logic yet - just schema declarations backed by
a metadata-driven schema spec.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/api/src/database/migrations/loot-and-rewards.migration.spec.ts

@@ -0,0 +1,97 @@
+import 'reflect-metadata';
+import { getMetadataArgsStorage } from 'typeorm';
+import { Character } from '../../characters/entities/character.entity';
+import { CharacterItem } from '../../items/entities/character-item.entity';
+import { ItemDefinition } from '../../items/entities/item-definition.entity';
+import { LootTable } from '../../loot/entities/loot-table.entity';
+import { LootTableEntry } from '../../loot/entities/loot-table-entry.entity';
+import { MonsterDefinition } from '../../monsters/entities/monster-definition.entity';
+import { CombatReward } from '../../rewards/entities/combat-reward.entity';
+import { CombatRewardItem } from '../../rewards/entities/combat-reward-item.entity';
+
+function uniqueIndexFor(target: unknown, columns: string[]) {
+  const index = getMetadataArgsStorage().indices.find(
+    (candidate) =>
+      candidate.target === target &&
+      columns.every((column) => candidate.columns?.includes(column)),
+  );
+  const indexMetadata = index as typeof index & {
+    options?: { unique?: boolean };
+    unique?: boolean;
+  };
+  return indexMetadata?.options?.unique ?? indexMetadata?.unique;
+}
+
+describe('loot and rewards schema', () => {
+  it('gives every combat at most one reward record', () => {
+    expect(uniqueIndexFor(CombatReward, ['combatId'])).toBe(true);
+  });
+
+  it('keeps one stack per character per item definition', () => {
+    expect(uniqueIndexFor(CharacterItem, ['characterId', 'itemDefinitionId'])).toBe(true);
+  });
+
+  it('keeps loot-table content keys and entry positions unique', () => {
+    expect(uniqueIndexFor(ItemDefinition, ['key'])).toBe(true);
+    expect(uniqueIndexFor(LootTable, ['key'])).toBe(true);
+    expect(uniqueIndexFor(LootTableEntry, ['lootTableId', 'position'])).toBe(true);
+    expect(uniqueIndexFor(LootTableEntry, ['lootTableId', 'itemDefinitionId'])).toBe(true);
+  });
+
+  it('maps reward and loot relations with the documented onDelete behavior', () => {
+    const relations = getMetadataArgsStorage().relations.filter((relation) =>
+      [CombatReward, CombatRewardItem, CharacterItem, LootTableEntry, MonsterDefinition].includes(
+        relation.target as never,
+      ),
+    );
+
+    expect(
+      relations.map((relation) => ({
+        onDelete: relation.options.onDelete,
+        propertyName: relation.propertyName,
+        target: relation.target,
+      })),
+    ).toEqual(
+      expect.arrayContaining([
+        expect.objectContaining({ onDelete: 'CASCADE', propertyName: 'combat', target: CombatReward }),
+        expect.objectContaining({ onDelete: 'RESTRICT', propertyName: 'character', target: CombatReward }),
+        expect.objectContaining({ onDelete: 'CASCADE', propertyName: 'combatReward', target: CombatRewardItem }),
+        expect.objectContaining({ onDelete: 'RESTRICT', propertyName: 'characterItem', target: CombatRewardItem }),
+        expect.objectContaining({ onDelete: 'RESTRICT', propertyName: 'itemDefinition', target: CombatRewardItem }),
+        expect.objectContaining({ onDelete: 'CASCADE', propertyName: 'character', target: CharacterItem }),
+        expect.objectContaining({ onDelete: 'RESTRICT', propertyName: 'itemDefinition', target: CharacterItem }),
+        expect.objectContaining({ onDelete: 'CASCADE', propertyName: 'lootTable', target: LootTableEntry }),
+        expect.objectContaining({ onDelete: 'RESTRICT', propertyName: 'itemDefinition', target: LootTableEntry }),
+        expect.objectContaining({ onDelete: 'RESTRICT', propertyName: 'lootTable', target: MonsterDefinition }),
+      ]),
+    );
+  });
+
+  it('adds the character silver column and the nullable monster loot table link', () => {
+    const columns = getMetadataArgsStorage().columns;
+
+    const silver = columns.find(
+      (candidate) => candidate.target === Character && candidate.propertyName === 'silver',
+    );
+    expect(silver).toBeDefined();
+    expect(silver?.options.type).toBe('integer');
+
+    const lootTableId = columns.find(
+      (candidate) =>
+        candidate.target === MonsterDefinition && candidate.propertyName === 'lootTableId',
+    );
+    expect(lootTableId).toBeDefined();
+    expect(lootTableId?.options.nullable).toBe(true);
+  });
+
+  it('stores drop chance as a numeric column so probabilities stay data-driven', () => {
+    const dropChance = getMetadataArgsStorage().columns.find(
+      (candidate) =>
+        candidate.target === LootTableEntry && candidate.propertyName === 'dropChance',
+    );
+
+    expect(dropChance?.options.type).toBe('numeric');
+    expect(dropChance?.options.precision).toBe(5);
+    expect(dropChance?.options.scale).toBe(4);
+  });
+});