web: PRO needs a proven address — email verification gates the studio

A signed-in account is served exactly like a guest until it opens the
verification link: watermarked 2048px export, no saving, no PRO frames,
GPS stamp or HDF. SMTP is declared in .env; with SMTP_HOST unset the link
goes to the container log. Allowlisted admins count as verified.

docker/frontend/src/Landing.tsx

@@ -180,7 +180,9 @@ export function Landing() {
   const [temp, setTemp] = useState(0);
   const [sat, setSat] = useState(100);
   const [con, setCon] = useState(100);
-  const [toast, setToast] = useState<string | null>(null);
+  // `lead` is the short bold tag in front of the message; the marketing lines
+  // share "Coming soon —", the verification ones carry their own.
+  const [toast, setToast] = useState<{ lead: string; text: string } | null>(null);
   const [user, setUser] = useState<User | null>(null);
   const [photos, setPhotos] = useState<Photo[]>([]);
   const [ratings, setRatings] = useState<Record<string, Rating>>({});
@@ -197,8 +199,13 @@ export function Landing() {
 
   const preset = PRESETS.find((p) => p.id === presetId) ?? PRESETS[0];
 
-  const showToast = useCallback((text: Txt | string) => {
-    setToast(typeof text === 'string' ? text : c(text));
+  const toastLead: Txt = { en: 'Coming soon —', vi: 'Sắp có —' };
+
+  const showToast = useCallback((text: Txt | string, lead?: Txt) => {
+    setToast({
+      lead: c(lead ?? toastLead),
+      text: typeof text === 'string' ? text : c(text),
+    });
     clearTimeout(toastTimer.current);
     toastTimer.current = setTimeout(() => setToast(null), 3400);
   }, [c]);
@@ -219,6 +226,32 @@ export function Landing() {
     reload();
   }, [reload]);
 
+  // The verification link in the letter redirects here with `?verified=1` (or
+  // `0` for a stale or unknown token). Say which it was, re-read the session so
+  // a just-proven account comes back PRO, and drop the flag so a reload does
+  // not repeat the toast.
+  useEffect(() => {
+    const params = new URLSearchParams(window.location.search);
+    const flag = params.get('verified');
+    if (flag === null) return;
+    params.delete('verified');
+    const rest = params.toString();
+    window.history.replaceState(null, '', `${window.location.pathname}${rest ? `?${rest}` : ''}${window.location.hash}`);
+    if (flag === '1') {
+      showToast(
+        { en: 'Your email is confirmed — the studio is unlocked.', vi: 'Đã xác thực email — studio đã mở khoá.' },
+        { en: 'Verified —', vi: 'Đã xác thực —' },
+      );
+      reload();
+    } else {
+      showToast(
+        { en: 'That verification link is invalid or has expired.', vi: 'Liên kết xác thực không hợp lệ hoặc đã hết hạn.' },
+        { en: 'Not verified —', vi: 'Chưa xác thực —' },
+      );
+    }
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
   // One vote. The visitor may change their mind: the API upserts under the same
   // address hash, so a second click replaces the first rather than stacking. A
   // vote that never lands is silently dropped — it is not worth a toast.
@@ -949,6 +982,7 @@ export function Landing() {
       {auth ? (
         <AuthModal
           initialMode={auth}
+          email={user?.email}
           onClose={() => setAuth(null)}
           onDone={() => {
             setAuth(null);
@@ -959,7 +993,7 @@ export function Landing() {
         />
       ) : null}
 
-      {toast ? <div className="lp-toast" role="status"><b>{c({ en: 'Coming soon —', vi: 'Sắp có —' })}</b> {toast}</div> : null}
+      {toast ? <div className="lp-toast" role="status"><b>{toast.lead}</b> {toast.text}</div> : null}
     </div>
   );
 }