mobile: drop the footer

The footer added a wordmark row and a "view desktop" escape hatch
below the Join confirmation. Neither is worth the visual weight on
a phone screen — the masthead already has the wordmark, and the
?view=desktop override still works as a manual URL. Page now ends
at the join confirmation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

protected/mobile/index.html

@@ -242,16 +242,6 @@
     </div>
   </section>
 
-  <footer class="m-foot">
-    <div class="m-foot-row">
-      <span class="m-foot-project">Project <em>Bifrost</em></span>
-      <img class="m-foot-fenja" src="/fenja/fenja-wordmark-black.svg" alt="Fenja AI" />
-    </div>
-    <p class="m-foot-note">
-      You&rsquo;re viewing the mobile-optimised version. <a href="/timeline?view=desktop">Open the desktop experience</a>.
-    </p>
-  </footer>
-
 </main>
 
 <script src="/mobile/mobile.js" defer></script>

protected/mobile/mobile.css

@@ -454,29 +454,3 @@ html, body {
   transform: rotate(-45deg);
 }
 .m-confirm-list em { font-style: italic; font-weight: 700; color: var(--accent); }
-
-/* ─── Footer ─────────────────────────────────────────────── */
-.m-foot {
-  padding: 26px 22px 40px;
-  border-top: 1px solid var(--line);
-}
-.m-foot-row {
-  display: flex;
-  justify-content: space-between;
-  align-items: center;
-  margin-bottom: 14px;
-}
-.m-foot-project {
-  font-family: "Newsreader", Georgia, serif;
-  font-size: 16px;
-  color: var(--ink);
-}
-.m-foot-project em { font-style: italic; font-weight: 700; color: var(--accent); }
-.m-foot-fenja { height: 18px; width: auto; display: block; opacity: 0.85; }
-.m-foot-note {
-  margin: 0;
-  font-family: "Manrope", system-ui, sans-serif;
-  font-size: 12px;
-  color: var(--ink-dim);
-}
-.m-foot-note a { color: var(--ink-soft); }