fix: bw/stats 404, gateway links, history crash

- swr.ts: remove useBandwidth(), drop bw from useDashboard()
- events/route.ts: skip bandwidth SSE (Kubo 0.28.0 unsupported)
- usage/page.tsx: remove getBWStats call + bw references
- helpers.ts: gatewayLink -> ipfs.maos.dedyn.io (subdomain only)
- upload/page.tsx: fix local gatewayLink (subdomain only)
- storage.ts: update default gatewayUrl, add defensive getHistory()

src/app/settings/page.tsx

@@ -5,7 +5,7 @@ import { getSettings, saveSettings, resetSettings, type PortalSettings } from '@
 import { useTheme } from '@/lib/theme';
 import PortalLayout from '@/app/layout-portal';
 import {
-  Settings, Globe, Server, HardDrive, RefreshCw,
+  Settings, Globe, Server, HardDrive, RefreshCw, Shield,
   Sun, Moon, Save, RotateCcw, Check, AlertTriangle,
 } from 'lucide-react';
 
@@ -16,6 +16,13 @@ function formatStorageMB(mb: number): string {
   return mb + ' MB';
 }
 
+function formatBytes(bytes: number): string {
+  if (bytes === 0) return '0 B';
+  const units = ['B', 'KB', 'MB', 'GB'];
+  const i = Math.floor(Math.log(bytes) / Math.log(1024));
+  return (bytes / Math.pow(1024, i)).toFixed(i > 0 ? 1 : 0) + ' ' + units[i];
+}
+
 /* ════════════════════════════ Page ════════════════════════════ */
 
 export default function SettingsPage() {
@@ -185,6 +192,90 @@ export default function SettingsPage() {
         </div>
       ),
     },
+    {
+      title: 'Upload Restrictions',
+      icon: Shield,
+      iconColor: 'text-accent-rose',
+      fields: (
+        <div className="space-y-4">
+          {/* Allowed file types */}
+          <div>
+            <label className="text-xs text-surface-400 mb-1.5 block">Allowed File Extensions</label>
+            <input
+              value={form.allowedFileTypes}
+              onChange={e => update('allowedFileTypes', e.target.value)}
+              placeholder=".jpg,.png,.pdf,.mp4 (leave empty for all)"
+              className={inputCls('allowedFileTypes')}
+            />
+            {errorMsg('allowedFileTypes')}
+            <p className="mt-1.5 text-[11px] text-surface-500">
+              Comma-separated extensions. Empty = all file types accepted.
+              Extension check is case-insensitive.
+            </p>
+          </div>
+
+          {/* Max file size */}
+          <div>
+            <label className="text-xs text-surface-400 mb-1.5 block">
+              Max File Size: <span className="text-surface-200 font-medium">{formatBytes(form.maxFileSize)}</span>
+            </label>
+            <div className="flex items-center gap-3">
+              <input
+                type="range"
+                min={1024}
+                max={1024 * 1024 * 1024}
+                step={1024 * 1024}
+                value={Math.max(1024, form.maxFileSize)}
+                onChange={e => update('maxFileSize', Number(e.target.value))}
+                className="flex-1 accent-brand-500 h-1.5 rounded-full appearance-none bg-surface-700 cursor-pointer"
+                style={{ accentColor: '#14b8a6' }}
+              />
+              <input
+                type="number"
+                min={0}
+                max={1024 * 1024 * 1024}
+                value={form.maxFileSize}
+                onChange={e => update('maxFileSize', Math.max(0, Number(e.target.value) || 0))}
+                className="w-24 rounded-lg bg-surface-900 border border-surface-700 px-2 py-1.5 text-xs text-surface-200 text-center focus:outline-none focus:border-brand-500"
+              />
+            </div>
+            <p className="mt-1.5 text-[11px] text-surface-500">
+              Maximum file size in bytes. 0 = unlimited.
+            </p>
+          </div>
+
+          {/* Max files per batch */}
+          <div>
+            <label className="text-xs text-surface-400 mb-1.5 block">
+              Max Files Per Upload: <span className="text-surface-200 font-medium">{form.maxFiles}</span>
+            </label>
+            <div className="flex items-center gap-3">
+              <input
+                type="range"
+                min={1}
+                max={100}
+                step={1}
+                value={form.maxFiles}
+                onChange={e => update('maxFiles', Number(e.target.value))}
+                className="flex-1 accent-brand-500 h-1.5 rounded-full appearance-none bg-surface-700 cursor-pointer"
+                style={{ accentColor: '#14b8a6' }}
+              />
+              <input
+                type="number"
+                min={1}
+                max={100}
+                value={form.maxFiles}
+                onChange={e => update('maxFiles', Math.max(1, Math.min(100, Number(e.target.value) || 0)))}
+                className="w-16 rounded-lg bg-surface-900 border border-surface-700 px-2 py-1.5 text-xs text-surface-200 text-center focus:outline-none focus:border-brand-500"
+              />
+            </div>
+            <p className="mt-1.5 text-[11px] text-surface-500">
+              Maximum number of files allowed in a single upload batch.
+            </p>
+          </div>
+        </div>
+      ),
+    },
     {
       title: 'Auto-Refresh',
       icon: RefreshCw,