fix: recover expired dashboard sessions (#309)

src/views.py

@@ -13,7 +13,7 @@ LOGIN_HTML = """<!doctype html>
 <title>Sign in · Stackchain Dashboard</title>
 <style>body{margin:0;background:#07111f;color:#eef6ff;font:16px system-ui;display:grid;min-height:100vh;place-items:center}main{box-sizing:border-box;width:min(90vw,24rem);padding:2rem;border:1px solid #29415d;border-radius:1rem;background:#0d1b2b}label,input,button{display:block;width:100%;box-sizing:border-box}input,button{min-height:48px;margin-top:.6rem;border-radius:.6rem;border:1px solid #49647f;padding:.75rem}button{margin-top:1rem;background:#55d6be;color:#06121b;font-weight:700}p{color:#a9bed3}</style></head>
 <body><main><h1>Operator sign in</h1><p>Enter the dashboard access token. It is exchanged for a private, short-lived session and is never stored on this device.</p>
-<form id="sign-in"><label>Access token<input name="access_token" type="password" autocomplete="current-password" required></label><button id="submit-sign-in">Sign in</button><p id="status" role="status"></p></form></main>
+<form id="sign-in"><label>Access token<input name="access_token" type="password" autocomplete="current-password" required></label><button id="submit-sign-in">Sign in</button><p id="status" role="status" aria-live="polite"></p></form></main>
 <script src="static/login.js"></script></body></html>"""