feat(ui): add banned IPs management to debug panel

- Add debug section for banned IPs with refresh button
- Implement fetchBannedIPs() function to display banned IPs in table
- Add adminUnban() function for unbanning IPs from UI
- Show IP, ban time, reason, banned by, and unban action in table

public/index.html

@@ -535,6 +535,11 @@
         color: var(--danger);
       }
 
+      .device-actions {
+        display: flex;
+        gap: 4px;
+      }
+
       .confirm-text {
         font-size: 15px;
         margin-bottom: 24px;
@@ -675,12 +680,31 @@
                   <th>Requests</th>
                   <th>Last Seen</th>
                   <th>User Agent</th>
+                  <th>Actions</th>
                 </tr>
               </thead>
               <tbody id="debug-devices-tbody"></tbody>
             </table>
           </div>
         </div>
+
+        <div class="debug-section">
+          <h3>🚫 Banned IPs</h3>
+          <div style="overflow-x: auto">
+            <table class="debug-table">
+              <thead>
+                <tr>
+                  <th>IP</th>
+                  <th>Banned At</th>
+                  <th>Reason</th>
+                  <th>Banned By</th>
+                  <th>Actions</th>
+                </tr>
+              </thead>
+              <tbody id="debug-banned-tbody"><tr><td colspan="5" style="color:var(--muted);text-align:center;">No banned IPs</td></tr></tbody>
+            </table>
+          </div>
+        </div>
       </div>
     </div>
 
@@ -903,7 +927,7 @@
       <div class="field">
         <label>Cache TTL (seconds)</label>
         <input type="number" id="view-cache-ttl" value="${cacheTtl}" min="0" max="86400" required>
-        <div class="hint">How long a render stays in cache. 0 = always re-render. Each access extends TTL.</div>
+        <div class="hint">How long a render stays in cache. 0 = always re-render.</div>
       </div>
 
       <div class="field" style="display:flex;gap:12px;">
@@ -1164,6 +1188,7 @@
         document.getElementById("debug-devices-tbody").innerHTML = data.devices
           .map((d) => {
             const ago = Math.round((Date.now() - d.lastSeen) / 1000);
+            const ipEnc = encodeURIComponent(d.ip);
             return `
       <tr>
         <td>${esc(d.ip)}</td>
@@ -1171,10 +1196,20 @@
         <td>${d.requestCount}</td>
         <td>${ago}s ago</td>
         <td class="url-cell" title="${esc(d.userAgent)}">${esc(d.userAgent.slice(0, 60))}</td>
+        <td>
+          <div class="device-actions">
+            <button class="btn btn-xs btn-ghost" onclick="adminRefresh('${ipEnc}')" title="Force cache refresh">↺</button>
+            <button class="btn btn-xs btn-ghost" onclick="adminDisconnect('${ipEnc}')" title="Disconnect">⏏</button>
+            <button class="btn btn-xs btn-danger" onclick="adminBan('${ipEnc}', '${esc(d.ip)}')" title="Ban IP">🚫</button>
+          </div>
+        </td>
       </tr>`;
           })
           .join("");
 
+        // ── Banned IPs table ──
+        fetchBannedIPs();
+
         if (!debugTickInterval) {
           debugTickInterval = setInterval(tickDebugValues, 500);
         }
@@ -1203,6 +1238,88 @@
         });
       }
 
+      // ═══════════════════════════════════════════════
+      // ADMIN ACTIONS
+      // ═══════════════════════════════════════════════
+
+      async function adminDisconnect(ipEnc) {
+        try {
+          await api("POST", "/api/admin/disconnect/" + ipEnc);
+          toast("Device disconnected");
+        } catch (err) {
+          toast(err.message, "error");
+        }
+      }
+
+      async function adminRefresh(ipEnc) {
+        try {
+          await api("POST", "/api/admin/refresh/" + ipEnc);
+          toast("Cache refreshed");
+        } catch (err) {
+          toast(err.message, "error");
+        }
+      }
+
+      function adminBan(ipEnc, ipDisplay) {
+        openModal(`
+    <h2>Ban IP</h2>
+    <div class="confirm-text">Ban <strong>${esc(ipDisplay)}</strong>? Future connections will receive 403.</div>
+    <div class="field">
+      <label>Reason</label>
+      <input type="text" id="ban-reason" placeholder="Reason (optional)" value="Banned by administrator">
+    </div>
+    <div class="modal-footer">
+      <button class="btn btn-ghost" onclick="closeModal()">Cancel</button>
+      <button class="btn btn-danger" onclick="doAdminBan('${ipEnc}', '${esc(ipDisplay)}')">Ban</button>
+    </div>`);
+      }
+
+      async function doAdminBan(ipEnc, ipDisplay) {
+        const reason = document.getElementById("ban-reason")?.value || "Banned by administrator";
+        try {
+          await api("POST", "/api/admin/ban/" + ipEnc, { reason });
+          closeModal();
+          toast(`Banned ${decodeURIComponent(ipEnc)}`);
+          fetchBannedIPs();
+        } catch (err) {
+          toast(err.message, "error");
+        }
+      }
+
+      async function adminUnban(ipEnc) {
+        try {
+          await api("POST", "/api/admin/unban/" + ipEnc);
+          toast("IP unbanned");
+          fetchBannedIPs();
+        } catch (err) {
+          toast(err.message, "error");
+        }
+      }
+
+      async function fetchBannedIPs() {
+        try {
+          const banned = await api("GET", "/api/banned");
+          const tbody = document.getElementById("debug-banned-tbody");
+          if (!tbody) return;
+          if (!banned.length) {
+            tbody.innerHTML = '<tr><td colspan="5" style="color:var(--muted);text-align:center;">No banned IPs</td></tr>';
+            return;
+          }
+          tbody.innerHTML = banned.map((b) => {
+            const ipEnc = encodeURIComponent(b.ip);
+            const dt = new Date(b.banned_at * 1000).toLocaleString();
+            return `
+      <tr>
+        <td>${esc(b.ip)}</td>
+        <td>${esc(dt)}</td>
+        <td>${esc(b.reason || "—")}</td>
+        <td>${esc(b.banned_by || "—")}</td>
+        <td><button class="btn btn-xs btn-ghost" onclick="adminUnban('${ipEnc}')">Unban</button></td>
+      </tr>`;
+          }).join("");
+        } catch { /* silent */ }
+      }
+
       // ═══════════════════════════════════════════════
       // KEYBOARD
       // ═══════════════════════════════════════════════