feat(ui): add enable/disable toggle for Ralph Wiggum tracker

Add ability to enable/disable the Ralph tracker:
- Per-session toggle in Session Options > Ralph Wiggum tab
- Global default toggle in App Settings

Changes:
- Add "Enable Tracker" toggle to ralph-tab in session options modal
- Add "Enable Ralph Wiggum Tracker" toggle to app settings modal
- Update /api/sessions/:id/inner-config endpoint to handle `enabled` param
- Add CSS for toggle switch component
- New sessions inherit global setting from app settings
- Setting is saved in innerConfig and synced with backend

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/web/public/styles.css

@@ -1466,6 +1466,77 @@ body {
   margin-top: 0.35rem;
 }
 
+/* Switch toggle for form rows */
+.form-row-switch {
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  flex-wrap: wrap;
+}
+
+.form-row-switch > label:first-child {
+  margin-bottom: 0;
+  min-width: 120px;
+}
+
+.form-row-switch .form-hint {
+  flex-basis: 100%;
+  margin-top: 0.25rem;
+}
+
+.switch {
+  position: relative;
+  display: inline-block;
+  width: 36px;
+  height: 20px;
+  flex-shrink: 0;
+}
+
+.switch input {
+  opacity: 0;
+  width: 0;
+  height: 0;
+}
+
+.switch .slider {
+  position: absolute;
+  cursor: pointer;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background-color: var(--bg-input);
+  border: 1px solid var(--border);
+  transition: 0.2s;
+  border-radius: 20px;
+}
+
+.switch .slider:before {
+  position: absolute;
+  content: "";
+  height: 14px;
+  width: 14px;
+  left: 2px;
+  bottom: 2px;
+  background-color: var(--text-muted);
+  transition: 0.2s;
+  border-radius: 50%;
+}
+
+.switch input:checked + .slider {
+  background-color: var(--accent);
+  border-color: var(--accent);
+}
+
+.switch input:checked + .slider:before {
+  transform: translateX(16px);
+  background-color: white;
+}
+
+.switch input:focus + .slider {
+  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.3);
+}
+
 .form-actions {
   display: flex;
   justify-content: flex-end;