Add registration status badges and auto-dismissing dashboard messages

Two consistency fixes requested after the payment-method work:

1. Registration status (pending/confirmed/partial_paid/paid/cancelled)
   was printed as a raw string on the user dashboard. Added
   RegistrationStatusBadge mirroring the existing EventStatusBadge
   pattern, using the same status colors already established on
   dashboard/admin/registrations.

2. Inline success/error banners across dashboard pages persisted
   indefinitely. Added a shared useDismissingState hook (drop-in
   useState replacement that auto-clears a truthy value after 7s,
   resetting the timer on each update) and swapped it in across ~24
   dashboard files. Excluded: message-only modal dialogs (ticket-
   scanning's success/error confirmations) and two states that mix
   live form-validation feedback with async results inside actively-
   open forms (the registration-edit modal's editError, the event
   create/edit modal's error) - those keep persisting until the user
   acts, since auto-hiding a "fix this field" message mid-edit would
   be a regression. Also fixed at-the-door's existing bespoke
   auto-dismiss timers (10s/15s, one mislabeled as "5s") to the same
   consistent 7s, and removed admin/settings' manual x dismiss button
   in favor of the same auto-only behavior.

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

frontend/src/app/dashboard/supervisor/at-the-door/page.tsx

@@ -5,6 +5,7 @@ import { useAuth } from "@/hooks/useAuth";
 import { useRouter } from "next/navigation";
 import { apiFetch } from "@/lib/api";
 import { scoreUser } from "@/lib/fuzzyMatch";
+import { useDismissingState } from "@/hooks/useDismissingState";
 
 type Mode = "registration" | "payment" | "tickets" | "refund";
 
@@ -154,30 +155,8 @@ export default function AtTheDoorPage() {
     const [mode, setMode] = useState<Mode>("registration");
 
     const [activeRegistration, setActiveRegistration] = useState<any | null>(null);
-    const [info, setInfo] = useState<string | null>(null);
-    const [error, setError] = useState<string | null>(null);
-
-    useEffect(() => {
-        if (!info) return;
-
-        const id = setTimeout(() => {
-            setInfo(null);
-        }, 10000); // ⏱ disappears after 5s
-
-        return () => clearTimeout(id);
-
-    }, [info]);
-
-    useEffect(() => {
-        if (!error) return;
-
-        const id = setTimeout(() => {
-            setError(null);
-        }, 15000); // errors linger slightly longer
-
-        return () => clearTimeout(id);
-
-    }, [error]);
+    const [info, setInfo] = useDismissingState<string | null>(null);
+    const [error, setError] = useDismissingState<string | null>(null);
 
     const handleRegistrationCreated = (registration: any) => {
         setActiveRegistration(registration);
@@ -1332,7 +1311,7 @@ function SendTicketsModal({ open, onClose, token, registration, setError, setInf
     const [phone, setPhone] = useState("");
     const [email, setEmail] = useState("");
     const [sending, setSending] = useState(false);
-    const [localError, setLocalError] = useState("");
+    const [localError, setLocalError] = useDismissingState("");
     const [localInfo, setLocalInfo] = useState("");
 
     useEffect(() => {
@@ -1369,7 +1348,7 @@ function SendTicketsModal({ open, onClose, token, registration, setError, setInf
                 },
             });
             setLocalInfo("Tickets sent successfully.");
-            setTimeout(() => { setLocalInfo(""); onClose(); }, 2000);
+            setTimeout(() => { setLocalInfo(""); onClose(); }, 7000);
         } catch (e: any) {
             setLocalError(e?.message || "Failed to send tickets");
         } finally {
@@ -1461,7 +1440,7 @@ function RefundModal({ open, onClose, token, registration, maxRefund, onRefunded
     const [method, setMethod] = useState("cash");
     const [reason, setReason] = useState("");
     const [saving, setSaving] = useState(false);
-    const [localError, setLocalError] = useState("");
+    const [localError, setLocalError] = useDismissingState("");
 
     useEffect(() => {
         if (open) { setAmount(""); setReason(""); setLocalError(""); }