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/components/auth/register-form.tsx

@@ -57,8 +57,16 @@ export function RegisterForm({
 		null,
 	);
 	const autoLoginStartedRef = useRef(false);
+	const [referralCode, setReferralCode] = useState("");
 	const strength = passwordStrength(password);
 
+	// The invite link is `/register?ref=<username>`; read it client-side so the
+	// attribution travels with the sign-up form without server state.
+	useEffect(() => {
+		const ref = new URLSearchParams(window.location.search).get("ref");
+		if (ref) setReferralCode(ref);
+	}, []);
+
 	// Successful sign-up: sign in with the submitted credentials and go
 	// straight to /me. If the automatic sign-in is refused (e.g. email
 	// verification required), fall back to the regular login page.
@@ -187,6 +195,23 @@ export function RegisterForm({
 					</div>
 				)}
 
+				{referralCode && (
+					<div
+						className="animate-fade-in-up flex items-center gap-2 p-3 rounded-lg text-sm font-semibold"
+						style={{
+							backgroundColor:
+								"color-mix(in srgb, var(--color-primary) 12%, transparent)",
+							color: "var(--color-primary-readable, var(--color-primary))",
+							border:
+								"1px solid color-mix(in srgb, var(--color-primary) 22%, transparent)",
+						}}
+					>
+						{t("invitedBy", { username: referralCode })}
+					</div>
+				)}
+
+				<input type="hidden" name="ref" value={referralCode} />
+
 				{/* Username & Email */}
 				<div className="space-y-2">
 					<div className="flex items-center gap-2">