Plex: try the server's LAN address first, allow a manual address

Connecting through plex.direct names failed from the container (DNS and
hairpin NAT). Try http://<lan-ip>:<port> first, verify the server's
machine identifier before sending the token, and let the user type an
address when discovery fails.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/app.js

@@ -550,11 +550,22 @@ async function plexPickServer() {
     if (!servers.length) { v.innerHTML = '<div class="wrap"><h1>Music</h1><p class="err">No Plex servers found on this account.</p></div>'; return; }
     v.innerHTML = `<div class="wrap"><h1>Music</h1><p class="sub">Choose a server</p><div class="list">${servers.map(s => `
       <button class="row" data-id="${esc(s.id)}"><span class="ic" style="background:#e5a00d">${icon('music')}</span>
-      <span class="grow"><b>${esc(s.name)}</b><small>${s.owned ? 'Yours' : 'Shared with you'}</small></span>${icon('chev', 'chev')}</button>`).join('')}</div><div class="err" id="pe"></div></div>`;
+      <span class="grow"><b>${esc(s.name)}</b><small>${s.owned ? 'Yours' : 'Shared with you'}</small></span>${icon('chev', 'chev')}</button>`).join('')}</div><div class="err" id="pe"></div><div id="pm"></div></div>`;
     v.querySelectorAll('button.row').forEach(b => b.onclick = async () => {
       b.disabled = true; $('#pe').textContent = '';
       try { await jfetch('/api/plex/server', { method: 'POST', body: JSON.stringify({ id: b.dataset.id }) }); px.sec = null; route(); }
-      catch (e) { b.disabled = false; $('#pe').textContent = e.message; }
+      catch (e) {
+        b.disabled = false; $('#pe').textContent = e.message;
+        // Offer a hand-typed address (e.g. the server's LAN address) when automatic discovery fails.
+        $('#pm').innerHTML = `<p class="sub">Know the server's address? Enter it (for example <b>http://192.168.1.10:32400</b>).</p>
+          <form id="pf2"><input type="url" id="pu" placeholder="http://192.168.1.10:32400" autocomplete="off" autocapitalize="off" required>
+          <div class="bar"><button class="btn">Try this address</button></div></form>`;
+        $('#pf2').onsubmit = async ev => {
+          ev.preventDefault(); $('#pe').textContent = '';
+          try { await jfetch('/api/plex/server', { method: 'POST', body: JSON.stringify({ id: b.dataset.id, uri: $('#pu').value.trim() }) }); px.sec = null; route(); }
+          catch (e2) { $('#pe').textContent = e2.message; }
+        };
+      }
     });
   } catch (e) { if (e.status === 401) return plexSignIn(); v.innerHTML = `<div class="wrap"><h1>Music</h1><p class="err">${esc(e.message)}</p></div>`; }
 }