Add encrypted envelope recipient state

webui/src/features/postbox/PostboxPage.tsx

@@ -999,7 +999,7 @@ function MessageDetail({
           resetKey={`${message.id}:${message.availability}`}
         >
           {message.availability === "withdrawn"
-            ? "This message was withdrawn. Its audit metadata remains visible, but its content and actions are unavailable."
+            ? "This message was withdrawn. Future access is blocked and audit metadata remains visible. Plaintext already decrypted, copied, exported, or printed cannot be retracted."
             : "This message has expired. Its audit metadata remains visible, but its content and actions are unavailable."}
         </DismissibleAlert>
       ) : null}
@@ -1026,6 +1026,12 @@ function MessageDetail({
           <div><dt>Address</dt><dd>{postbox?.address || "Not loaded"}</dd></div>
           <div><dt>Producer</dt><dd>{producerLabel(message)}</dd></div>
           <div><dt>Encryption profile</dt><dd>{message.encryption_profile} · epoch {message.key_epoch}</dd></div>
+          {message.wrapped_keys.length ? (
+            <div><dt>Key envelopes</dt><dd>{message.wrapped_keys.length}</dd></div>
+          ) : null}
+          {message.external_recipient_tokens.length ? (
+            <div><dt>External grants</dt><dd>{message.external_recipient_tokens.length}</dd></div>
+          ) : null}
         </dl>
       </section>
       <section className="postbox-body">