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/index.html

@@ -309,6 +309,17 @@
                             </label>
                         </div>
 
+                        <div class="config-item">
+                            <label class="checkbox-label">
+                                <input type="checkbox" id="folder-scan-enabled">
+                                <span class="checkbox-custom"></span>
+                                <span data-text="folder-scan-enabled">Run folder maintenance (NFO repair, renaming, poster checks)</span>
+                            </label>
+                            <small class="config-hint" data-text="folder-scan-hint">
+                                Automatically repair NFOs, rename folders, and check posters during scheduled runs.
+                            </small>
+                        </div>
+
 
                         <div class="config-item scheduler-status" id="scheduler-status">
                             <div class="scheduler-info">