feat(referrals): add referral attribution and daily login rewards

- Track referral attribution at registration via ?ref code with
  same-IP and duplicate-pair guards
- Add daily login rewards with streak tracking, claim flow and
  sendCurrency payout backed by RCON with DB fallback
- Add admin pages for referral settings and the daily reward schedule
- Add migration 0033 with tables, seed schedule, settings and ACL grants
- Add admin.referrals.* and admin.dailyrewards.* permission slugs
- Localize new copy in en, nl and it

src/lib/services/daily-rewards.test.ts

@@ -0,0 +1,56 @@
+import { describe, expect, it, vi } from "vitest";
+
+vi.mock("server-only", () => ({}));
+vi.mock("@/lib/db", () => ({ db: {} }));
+vi.mock("./site-settings", () => ({
+	siteSettings: { getBool: async () => true },
+}));
+
+import {
+	type DailyRewardRow,
+	rewardForStreak,
+	shiftDayKey,
+} from "./daily-rewards";
+
+describe("daily reward date math", () => {
+	it("shifts day keys across month and year boundaries", () => {
+		expect(shiftDayKey("2026-03-01", -1)).toBe("2026-02-28");
+		expect(shiftDayKey("2026-01-01", 31)).toBe("2026-02-01");
+		expect(shiftDayKey("2026-12-31", 1)).toBe("2027-01-01");
+		expect(shiftDayKey("2026-02-28", 1)).toBe("2026-03-01");
+	});
+});
+
+describe("daily reward streak resolution", () => {
+	const rewards: DailyRewardRow[] = [
+		{ id: "1", day: 1, currency: "duckets", amount: 50 },
+		{ id: "2", day: 2, currency: "duckets", amount: 60 },
+		{ id: "5", day: 5, currency: "diamonds", amount: 2 },
+	];
+
+	it("resolves configured days and repeats the cycle", () => {
+		expect(rewardForStreak(rewards, 1)?.day).toBe(1);
+		expect(rewardForStreak(rewards, 2)?.day).toBe(2);
+		expect(rewardForStreak(rewards, 5)?.day).toBe(5);
+		// The cycle is the highest configured day: 5 → back to day 1.
+		expect(rewardForStreak(rewards, 6)?.day).toBe(1);
+		expect(rewardForStreak(rewards, 7)?.day).toBe(2);
+		expect(rewardForStreak(rewards, 10)?.day).toBe(5);
+	});
+
+	it("falls back to the day-1 reward for unconfigured days", () => {
+		// Days 3 and 4 are not configured in the schedule → day-1 reward.
+		expect(rewardForStreak(rewards, 3)?.day).toBe(1);
+		expect(rewardForStreak(rewards, 4)?.day).toBe(1);
+	});
+
+	it("returns null for empty schedules or non-positive streaks", () => {
+		expect(rewardForStreak([], 3)).toBeNull();
+		expect(
+			rewardForStreak(
+				[{ id: "1", day: 3, currency: "credits", amount: 10 }],
+				0,
+			),
+		).toBeNull();
+	});
+});