feat(system-reset): add system reset and factory reset feature

- Add FACTORY_RESET_ON_STARTUP and ENABLE_FACTORY_RESET config settings
- Create app/utils/system_reset.py with core reset logic (wipe DB + files, reimport)
- Create app/api/system_reset.py with admin-only API endpoints
- Create app/views/system_reset.py with admin-only UI view
- Create frontend/templates/system_reset.html with confirmation dialogs
- Auto-reset on startup when FACTORY_RESET_ON_STARTUP=true
- Re-import uses watch folder mechanism for re-ingestion
- Register routers in API and views init files
- Add i18n keys and SETTING_METADATA entries
- Add nav links in base.html (desktop + mobile)

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/views/__init__.py

@@ -34,6 +34,7 @@ from app.views.share import router as share_router
 from app.views.shared_links import router as shared_links_router
 from app.views.status import router as status_router
 from app.views.subscriptions import router as subscriptions_router  # Pricing + subscription pages
+from app.views.system_reset import router as system_reset_router  # System reset / factory reset
 from app.views.wizard import router as wizard_router
 
 # Create a main router that includes all the view routers
@@ -67,3 +68,4 @@ router.include_router(scheduled_jobs_router)  # Admin scheduled batch jobs
 router.include_router(audit_logs_router)  # Comprehensive audit log viewer
 router.include_router(help_router)  # Built-in help / How-To docs
 router.include_router(compliance_router)  # Compliance templates dashboard
+router.include_router(system_reset_router)  # System reset / factory reset