Fix remaining frontend security issues (3 medium, 2 low)

- Escape user-input port number in app-selector innerHTML
- Replace inline onclick with addEventListener in backup history (HTML entity decode bypass)
- Add Content-Security-Policy meta tag with script hash
- Replace document.write with textContent for footer year
- Filter __proto__/constructor/prototype in Object.assign calls

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

status/index.html

@@ -8,6 +8,7 @@
   <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
   <meta http-equiv="Pragma" content="no-cache" />
   <meta http-equiv="Expires" content="0" />
+  <meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self' 'sha256-6JZtsKK/PZthh+stCmmCvC2QxCiyk6SwZCBjXE+kYr0='; style-src 'self' 'unsafe-inline'; img-src 'self' https://cdn.jsdelivr.net data:; connect-src 'self' https://api.open-meteo.com https://geocoding-api.open-meteo.com; font-src 'self'; object-src 'none'; base-uri 'self'; form-action 'self'">
 
   <link rel="icon" href="/assets/dashcaddy-favicon.ico" sizes="any">
   <link rel="icon" type="image/png" sizes="192x192" href="/assets/icon-192.png">
@@ -534,13 +535,15 @@
           if (el) el.style.display = 'none';
         }
       }
+      var yr = document.getElementById('footer-year');
+      if (yr) yr.textContent = new Date().getFullYear();
     })();
   </script>
 
   <!-- Clock rendering is handled by the bundled clock.js module -->
 
   <footer class="dashcaddy-footer">
-    <span class="footer-copy">&copy; <script>document.write(new Date().getFullYear())</script></span>
+    <span class="footer-copy">&copy; <span id="footer-year"></span></span>
     <img src="/assets/sami7777-logo.png" alt="samiahmed7777" class="footer-logo">
   </footer>
 

status/js/app-selector.js

@@ -587,7 +587,7 @@
 
       const result = await checkPortAvailability(portToCheck);
       if (result.available) {
-        portStatus.innerHTML = `<span style="color: #4caf50;">Port ${portToCheck} is available</span>`;
+        portStatus.innerHTML = `<span style="color: #4caf50;">Port ${escapeHtml(String(portToCheck))} is available</span>`;
       } else {
         const suggestedPort = await getSuggestedPort(defaultPort);
         portStatus.innerHTML = `

status/js/backup-restore.js

@@ -381,7 +381,7 @@
             <span style="font-weight: 500;">${escapeHtml(bk.name || 'backup')}</span>
             <div style="display: flex; align-items: center; gap: 8px;">
               <span class="status-badge ${bk.status === 'success' ? 'success' : 'down'}">${escapeHtml(bk.status)}</span>
-              ${bk.status === 'success' ? `<button onclick="window.__restoreServerBackup('${escapeHtml(bk.id)}')" style="padding: 3px 8px; font-size: 0.75rem;">Restore</button>` : ''}
+              ${bk.status === 'success' ? `<button class="backup-restore-btn" data-backup-id="${escapeHtml(bk.id)}" style="padding: 3px 8px; font-size: 0.75rem;">Restore</button>` : ''}
             </div>
           </div>
           <div style="font-size: 0.75rem; color: var(--muted);">
@@ -392,6 +392,10 @@
       }
       html += '</div>';
       historyContainer.innerHTML = html;
+      // Wire restore buttons with addEventListener (not inline onclick — HTML entity decode bypass)
+      historyContainer.querySelectorAll('.backup-restore-btn').forEach(btn => {
+        btn.addEventListener('click', () => window.__restoreServerBackup(btn.dataset.backupId));
+      });
     } catch (e) {
       historyContainer.innerHTML = `<div class="panel-empty" style="color: var(--bad-fg);">Failed: ${escapeHtml(e.message)}</div>`;
     }

status/js/globals.js

@@ -47,8 +47,10 @@ const SITE = {
         SITE.dnsIp = c.dns.ip || '';
         SITE.dnsPort = c.dns.port || DC.DEFAULTS.DNS_PORT;
       }
-      if (c.dnsServers) {
-        Object.assign(SITE.dnsServers, c.dnsServers);
+      if (c.dnsServers && typeof c.dnsServers === 'object') {
+        for (const [k, v] of Object.entries(c.dnsServers)) {
+          if (k !== '__proto__' && k !== 'constructor' && k !== 'prototype') SITE.dnsServers[k] = v;
+        }
       }
       if (c.configurationType) SITE.configurationType = c.configurationType;
       if (c.domain) SITE.domain = c.domain;
@@ -352,7 +354,12 @@ const AppState = {
   },
   updateApp(id, changes) {
     const app = this._apps.find(a => a.id === id);
-    if (app) { Object.assign(app, changes); DC_BUS.emit('apps:changed', this._apps); }
+    if (app) {
+      for (const [k, v] of Object.entries(changes)) {
+        if (k !== '__proto__' && k !== 'constructor' && k !== 'prototype') app[k] = v;
+      }
+      DC_BUS.emit('apps:changed', this._apps);
+    }
     return app;
   }
 };