feat: age verification with an ID document (Didit), and closed registration

Age: a Didit provider behind the vendor-neutral age interface. A person
verifies once (ID document, passive liveness, face match) and all their
linked IMVU accounts count as adult. Webhooks are checked against Didit's
signatures; only "over 18" is kept. A later answer replaces an earlier one
(an approval taken back is revoked). Checks are limited: one unfinished
check per person, 3 in 30 days, none once verified, and a monthly cap
(DIDIT_MONTHLY_LIMIT, default 30: Didit's free plan is $10 of credit a
month and a check costs $0.30). The Account page gets an Age Verification
card.

Registration: open or closed, an admin's setting in the console
(default from REGISTRATION). Closed: new accounts can only sign in until
a moderator approves them (or declines, deleting the account); the
website shows them a waiting page and the API treats them as signed out.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/account/age-card.tsx

@@ -0,0 +1,68 @@
+import { ActionForm, SubmitButton } from "@/components/forms";
+import { Tag } from "@/components/status";
+import { TimeAgo } from "@/components/time";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+import type { AgeInfo } from "@/lib/api";
+import { startAgeCheck } from "./actions";
+
+/** The person's own age check (an ID document, say), which covers all their IMVU accounts. */
+export function AgeCard({ age, back }: { age: AgeInfo; back: boolean }) {
+  const ways = age.providers.filter((p) => p.scope === "person");
+  if (ways.length === 0) return null;
+  const now = Date.now();
+  const verified = age.checks.find(
+    (c) => c.status === "complete" && c.overEighteen && (!c.expiresAt || new Date(c.expiresAt).getTime() > now),
+  );
+  const latest = age.checks[0];
+  const pending = latest?.status === "pending" ? latest : undefined;
+  const vendorOf = (id: string) => age.providers.find((p) => p.id === id)?.vendor ?? id;
+
+  return (
+    <Card>
+      <CardHeader>
+        <CardTitle>Age Verification</CardTitle>
+      </CardHeader>
+      <CardContent className="space-y-4 text-sm">
+        {verified ? (
+          <p className="flex flex-wrap items-center gap-2">
+            <Tag tone="adult">Age verified</Tag>
+            <span className="text-muted-foreground">
+              with {vendorOf(verified.provider)} <TimeAgo iso={verified.checkedAt ?? verified.createdAt} />. All your
+              IMVU accounts count as adult.
+            </span>
+          </p>
+        ) : (
+          <>
+            {pending ? (
+              <p>
+                {back
+                  ? "Thanks. Your check is being processed; this page shows the result when it's done."
+                  : "Your check isn't finished yet."}
+              </p>
+            ) : latest?.status === "complete" && !latest.overEighteen ? (
+              <p>Your last check found you're under 18.</p>
+            ) : latest?.status === "failed" || latest?.status === "revoked" ? (
+              <p>Your last check didn&apos;t pass. You can try again.</p>
+            ) : (
+              <p className="text-muted-foreground">
+                Verify your age once to count as adult on all your IMVU accounts, not only those IMVU has age verified.
+              </p>
+            )}
+            {ways.map((p) => (
+              <ActionForm key={p.id} action={startAgeCheck} fields={{ provider: p.id }}>
+                <div className="space-y-2">
+                  <SubmitButton variant={pending && pending.provider !== p.id ? "outline" : "default"} pendingLabel="Starting…">
+                    {pending?.provider === p.id ? "Continue check" : `Verify with ${p.label}`}
+                  </SubmitButton>
+                  <p className="text-xs text-muted-foreground">
+                    Done by {p.vendor}. T5DE only keeps whether you&apos;re over 18, never your ID, photo or birth date.
+                  </p>
+                </div>
+              </ActionForm>
+            ))}
+          </>
+        )}
+      </CardContent>
+    </Card>
+  );
+}