Listen without a pl8list account

"start listening" on the sign-in page makes a guest: a user with a negative
id and a session of its own, so the feed, likes, follows and radio work as
for anyone. Signing in with pl8list later moves the guest's plays, likes and
follows to the account. Signing out as a guest deletes it; guests whose
session ran out are purged hourly. New guests are capped at 10 per IP and
hour, and that limiter forgets IPs hourly. The privacy policy covers guests.

web/index.html

@@ -65,6 +65,10 @@
     <div class="login-box">
       <h1><svg class="login-mark" aria-hidden="true"><use href="#i-rewind"/></svg>pl8list <b>rewind</b></h1>
       <p class="tagline">endless riddim from pl8list. like it, and it comes back.</p>
+      <div id="guest-start">
+        <button type="button" id="guest-btn" class="primary"><svg><use href="#i-play"/></svg> start listening</button>
+        <p class="or">no account needed. or sign in with pl8list to bring your follows and likes along.</p>
+      </div>
       <form id="email-form">
         <label for="email">sign in with your pl8list email</label>
         <input id="email" type="email" name="email" autocomplete="email" required placeholder="you@example.com">
@@ -90,11 +94,11 @@
       <button type="button" id="login-cancel" class="link" hidden>cancel, keep using the app</button>
       <p id="login-error" role="alert"></p>
       <p class="fineprint">
-        No account? <a href="https://pl8list.com/signup" target="_blank" rel="noopener">sign up on pl8list</a>.
-        This site is not affiliated with pl8list. Your email and code go to pl8list, which signs this
-        server in for you. Unless you choose to stay connected, we use that pl8list login once to read
-        your feed and library, then log it out; it is never stored. We keep your pl8list handle, the
-        artists you follow and what you play and like, to pick tracks for you.
+        This site is not affiliated with pl8list. Without an account we keep what you play, like and
+        follow under a random cookie, to pick tracks for you; signing out deletes it. Your email and code
+        go to pl8list, which signs this server in for you. Unless you choose to stay connected, we use
+        that pl8list login once to read your feed and library, then log it out; it is never stored. We
+        keep your pl8list handle, the artists you follow and what you play and like.
       </p>
       <p class="fineprint legal-links">
         <a href="/datenschutz">Datenschutz / privacy</a> · <a href="/impressum">Impressum</a>