Settings ⚙ button now links to /settings page with left nav sidebar

The React tab bar's Settings button previously showed a minimal inline
component. Now it navigates to /settings which has the full settings
page with left sidebar navigation and category views.

ui/src/App.tsx

@@ -655,7 +655,11 @@ function PedalContent() {
         {/* ── Tab Bar ── */}
         <div className="pedal-tabbar">
           {TABS.map(t => (
-            <div key={t.id} className={`pedal-tab ${tab === t.id ? 'pedal-tab-active' : ''}`} onClick={() => setTab(t.id)}>
+            <div key={t.id} className={`pedal-tab ${tab === t.id ? 'pedal-tab-active' : ''}`}
+              onClick={() => {
+                if (t.id === 'settings') { window.location.href = '/settings'; return; }
+                setTab(t.id);
+              }}>
               <span className="pedal-tab-icon">{t.icon}</span>
               {t.label}
             </div>