test(slice-0.4): assert migration SQL and top-bar silver/XP rendering

Adds a real-SQL-inspection test for CreateLootAndRewards1788600000000
(mirroring the visible-vertical-slice pattern) so the one-reward-per-combat
unique index and other DB-level invariants can't be silently deleted
without failing a test, and asserts the TopBar renders character.silver
and character.experience values already present in the app.spec.ts fixture.

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

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

@@ -1,5 +1,6 @@
 import 'reflect-metadata';
-import { getMetadataArgsStorage } from 'typeorm';
+import { getMetadataArgsStorage, QueryRunner } from 'typeorm';
+import { CreateLootAndRewards1788600000000 } from './1788600000000-CreateLootAndRewards';
 import { Character } from '../../characters/entities/character.entity';
 import { CharacterItem } from '../../items/entities/character-item.entity';
 import { ItemDefinition } from '../../items/entities/item-definition.entity';
@@ -94,4 +95,53 @@ describe('loot and rewards schema', () => {
     expect(dropChance?.options.precision).toBe(5);
     expect(dropChance?.options.scale).toBe(4);
   });
+
+  it('emits the real SQL that enforces the schema invariants, not just entity decorators', async () => {
+    // synchronize: false means entity decorators never touch the real database -
+    // only the raw SQL emitted by the migration itself does. Assert on that SQL
+    // directly so deleting a constraint here would fail this test.
+    const query = jest.fn().mockResolvedValue(undefined);
+    const queryRunner = { query } as unknown as QueryRunner;
+    const migration = new CreateLootAndRewards1788600000000();
+
+    await migration.up(queryRunner);
+
+    const upQueries = query.mock.calls.map(([sql]) => sql as string);
+
+    expect(upQueries).toEqual(
+      expect.arrayContaining([
+        // The database half of the "one reward per combat" invariant (spec §7, §37).
+        expect.stringContaining('CREATE UNIQUE INDEX "IDX_combat_rewards_combat"'),
+        expect.stringContaining('CREATE UNIQUE INDEX "IDX_character_items_character_item"'),
+        expect.stringContaining('CREATE UNIQUE INDEX "IDX_combat_reward_items_reward_item"'),
+        expect.stringContaining('ALTER TABLE "characters" ADD COLUMN "silver"'),
+        expect.stringContaining('ALTER TABLE "monster_definitions" ADD COLUMN "loot_table_id"'),
+      ]),
+    );
+
+    const checkConstraints = upQueries.filter((sql) => sql.includes('CHECK ('));
+    expect(checkConstraints.length).toBeGreaterThan(0);
+    expect(
+      checkConstraints.some(
+        (sql) =>
+          sql.includes('CHK_loot_table_entries_drop_chance') ||
+          sql.includes('CHK_character_items_quantity'),
+      ),
+    ).toBe(true);
+
+    await migration.down(queryRunner);
+
+    const downQueries = query.mock.calls
+      .slice(upQueries.length)
+      .map(([sql]) => sql as string);
+
+    // Proves down() is real and reverses the up() migration, not a no-op.
+    expect(downQueries).toEqual(
+      expect.arrayContaining([
+        expect.stringContaining('DROP TABLE "combat_rewards"'),
+        expect.stringContaining('DROP TABLE "character_items"'),
+        'ALTER TABLE "characters" DROP COLUMN "silver"',
+      ]),
+    );
+  });
 });