feat: recall-on-restore, logout, and mail/contact export-import

web/index.html

@@ -41,6 +41,8 @@
     <button id="create-identity">create a new identity</button>
     <span>or restore from a saved seed:</span>
     <input id="restore-seed" placeholder="64 hex characters" spellcheck="false">
+    <input id="restore-address" placeholder="alice@example.org (if already registered)"
+           spellcheck="false">
     <button id="restore-identity">restore</button>
   </div>
 </main>
@@ -128,6 +130,19 @@
     <div id="identity-card"></div>
   </section>
 
+  <section>
+    <h3>backup</h3>
+    <p class="hint">Mail, once fetched, exists only here — the server deletes it as it's picked up
+      (SPEC.md §5). This backs up the local inbox, sent mail, contacts and pinned servers into one
+      file. It never includes the seed: that has its own reveal-and-copy flow above, meant for a
+      password manager, not a downloadable file.</p>
+    <div class="backup-row">
+      <button type="button" id="export-data">export</button>
+      <button type="button" id="import-data-trigger">import</button>
+      <input id="import-data" type="file" accept="application/json" hidden>
+    </div>
+  </section>
+
   <footer><button id="settings-close">close</button></footer>
 </dialog>