feat: area admin con editor tiptap, api crud e upload immagini

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/pages/admin/login.astro

@@ -0,0 +1,34 @@
+---
+import Admin from '../../layouts/Admin.astro';
+import { getDb } from '../../lib/db';
+import { login, SESSION_COOKIE } from '../../lib/auth';
+import { rateLimit } from '../../lib/rate-limit';
+export const prerender = false;
+
+let error = '';
+if (Astro.request.method === 'POST') {
+  if (!rateLimit(`login:${Astro.clientAddress}`, 5, 15 * 60 * 1000)) {
+    error = 'Troppi tentativi: riprova tra 15 minuti.';
+  } else {
+    const form = await Astro.request.formData();
+    const token = login(getDb(), String(form.get('username') ?? ''), String(form.get('password') ?? ''));
+    if (token) {
+      Astro.cookies.set(SESSION_COOKIE, token, {
+        httpOnly: true, sameSite: 'lax', path: '/',
+        secure: import.meta.env.PROD, maxAge: 7 * 24 * 3600,
+      });
+      return Astro.redirect('/admin');
+    }
+    error = 'Credenziali non valide.';
+  }
+}
+---
+<Admin title="Login">
+  <h1>Accesso</h1>
+  {error && <p style="color:#a33">{error}</p>}
+  <form method="post" style="max-width:360px">
+    <input class="afield" name="username" placeholder="Utente" required autocomplete="username" />
+    <input class="afield" type="password" name="password" placeholder="Password" required autocomplete="current-password" />
+    <button class="abtn" type="submit">Entra</button>
+  </form>
+</Admin>