test: cover getRedeemedCodesByUsers discordId chunking path

Add a test that passes 996 discordIds with a single code (chunk size =
999 - 1 - 3 = 995) to exercise the second loop iteration, restoring
100% branch coverage on codeManager.ts.

Signed-off-by: Michael Cramer <michael@bigmichi1.de>

Author: BigMichi1

src/bot/database/codeManager.test.ts

@@ -511,6 +511,14 @@ describe('getRedeemedCodesByUsers', () => {
       'Too many codes provided to getRedeemedCodesByUsers'
     );
   });
+
+  test('chunks large discordIds lists to stay within SQLite param limit', async () => {
+    await codeManager.addRedeemedCode('CODE1234ABCD', USER_A, 'Success');
+    // With 1 code: chunkSize = 999 - 1 - 3 = 995. 996 ids forces a second chunk iteration.
+    const manyIds = [USER_A, ...Array.from({ length: 995 }, (_, i) => `fake-user-${i}`)];
+    const result = await codeManager.getRedeemedCodesByUsers(['CODE1234ABCD'], manyIds);
+    expect(result.get(USER_A)?.has('CODE1234ABCD')).toBe(true);
+  });
 });
 
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