feat(scheduler): add folder_scan_enabled toggle to SchedulerConfig

- Add folder_scan_enabled boolean field (default false) to SchedulerConfig
- Update data/config.json example with new field
- Add checkbox to setup.html and include in JS payload
- Handle field in auth.py setup endpoint
- Expose field in scheduler API response
- Log and return field in scheduler_service.py
- Update docs/CONFIGURATION.md and docs/ARCHITECTURE.md
- Update index.html UI, app.js and scheduler-config.js handlers
- Verified backward compatibility: old configs load with default False

src/server/web/templates/setup.html

@@ -479,6 +479,13 @@
                                 <span>Auto-download missing episodes after rescan</span>
                             </label>
                         </div>
+                        <div class="form-group">
+                            <label class="form-checkbox">
+                                <input type="checkbox" id="scheduler_folder_scan" name="scheduler_folder_scan">
+                                <span>Run folder maintenance (NFO repair, renaming, poster checks)</span>
+                            </label>
+                            <div class="form-help">Automatically repair NFOs, rename folders, and check posters during scheduled runs</div>
+                        </div>
                     </div>
                 </div>
 
@@ -761,6 +768,7 @@
                 scheduler_schedule_time: document.getElementById('scheduler_schedule_time').value || '03:00',
                 scheduler_schedule_days: Array.from(document.querySelectorAll('.scheduler-day-setup-cb:checked')).map(cb => cb.value),
                 scheduler_auto_download_after_rescan: document.getElementById('scheduler_auto_download').checked,
+                scheduler_folder_scan_enabled: document.getElementById('scheduler_folder_scan').checked,
                 logging_level: document.getElementById('logging_level').value,
                 logging_file: document.getElementById('logging_file').value.trim() || null,
                 logging_max_bytes: document.getElementById('logging_max_bytes').value ?