feat(branding): system name/logo, horizontal logo on all pages

public/login.html

@@ -9,7 +9,10 @@
 :root{--bg:#f5f5f5;--card:#fff;--border:#e5e5e5;--accent:#2563eb;--text:#171717;--muted:#737373;--radius:12px}
 body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;background:var(--bg);color:var(--text);min-height:100dvh;display:flex;align-items:center;justify-content:center}
 .login{max-width:320px;width:100%;text-align:center;background:var(--card);border:1px solid var(--border);border-radius:16px;padding:40px 32px}
-.login h1{font-size:1.3rem;font-weight:600;margin-bottom:24px}
+.login .brand{display:flex;flex-direction:column;align-items:center;gap:14px;margin-bottom:24px}
+.login .brand .logo{height:48px;width:auto;min-width:48px;border-radius:14px;background:var(--bg);border:1px solid var(--border);display:none;align-items:center;justify-content:center;overflow:hidden}
+.login .brand .logo img{max-width:100%;max-height:100%;object-fit:contain}
+.login h1{font-size:1.3rem;font-weight:600;margin:0}
 .login input{width:100%;background:var(--bg);border:1px solid var(--border);color:var(--text);border-radius:var(--radius);padding:14px 16px;font-size:.95rem;outline:none;margin-bottom:12px;text-align:center}
 .login input:focus{border-color:var(--accent)}
 .login button{width:100%;background:var(--accent);color:#fff;border:none;border-radius:var(--radius);padding:14px;font-size:1rem;font-weight:600;cursor:pointer}
@@ -22,7 +25,10 @@ body{font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;b
 </head>
 <body>
 <div class="login">
-  <h1>Админ-панель</h1>
+  <div class="brand">
+    <div class="logo" id="loginLogo"></div>
+    <h1 id="loginTitle">Админ-панель</h1>
+  </div>
   <input type="text" id="userInput" placeholder="Логин" autocomplete="username" autofocus>
   <input type="password" id="pwdInput" placeholder="Пароль" autocomplete="current-password">
   <input type="text" id="hpWebsite" tabindex="-1" autocomplete="off" style="display:none" value="">