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/index.html

@@ -376,6 +376,15 @@
 
           <!-- Ralph Wiggum Tab Content -->
           <div class="modal-tab-content hidden" id="ralph-tab">
+            <div class="form-row form-row-switch">
+              <label>Enable Tracker</label>
+              <label class="switch">
+                <input type="checkbox" id="modalRalphEnabled">
+                <span class="slider"></span>
+              </label>
+              <span class="form-hint">Enable Ralph Wiggum tracker for this session (auto-detects loops and todos)</span>
+            </div>
+
             <div class="form-row">
               <label>Completion Phrase</label>
               <input type="text" id="modalRalphPhrase" placeholder="e.g., COMPLETE, DONE, FINISHED">
@@ -457,6 +466,14 @@
             <input type="text" id="appSettingsDefaultDir" placeholder="~/projects">
             <span class="form-hint">Default directory for new sessions.</span>
           </div>
+          <div class="form-row form-row-switch">
+            <label>Enable Ralph Wiggum Tracker</label>
+            <label class="switch">
+              <input type="checkbox" id="appSettingsRalphEnabled">
+              <span class="slider"></span>
+            </label>
+            <span class="form-hint">Enable tracker by default for new sessions. When disabled, tracker auto-enables when Ralph patterns are detected.</span>
+          </div>
         </div>
         <div class="form-actions">
           <button class="btn-toolbar" onclick="app.closeAppSettings()">Cancel</button>