fix: merge main into feature branch - resolve all 18 conflicts cleanly

Merges origin/main (v0.155.0) into the classification feature branch,
resolving all 18 conflicted files by accepting main's version and
re-applying only classification-specific additions:

- Renumber migration from 037 to 038 (chains from 037_user_sessions)
- Re-add ClassificationRuleModel to models.py, env.py, conftest.py
- Re-add classification_rules_router to api/__init__.py
- All session management, QR auth, and devices code preserved from main

Migration chain validated. 62 classification tests pass.

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

frontend/translations/en.json

@@ -608,6 +608,37 @@
   "dashboard.title": "Dashboard",
   "dashboard.total_files": "Total Files",
   "dashboard.welcome": "Welcome to DocuElevate",
+  "devices.col_created": "Connected",
+  "devices.col_device": "Device",
+  "devices.col_last_ip": "Last IP",
+  "devices.col_last_seen": "Last Seen",
+  "devices.col_last_used": "Last Used",
+  "devices.col_platform": "Platform",
+  "devices.col_push_token": "Push Token",
+  "devices.col_status": "Status",
+  "devices.col_token_prefix": "Token Prefix",
+  "devices.confirm_deactivate_device": "Remove this device? It will stop receiving push notifications.",
+  "devices.confirm_revoke_token": "Revoke access for this device? It will need to log in again.",
+  "devices.deactivate_device": "Remove",
+  "devices.device_removed_success": "Device removed successfully.",
+  "devices.heading": "Mobile Devices",
+  "devices.intro": "Manage your mobile app connections and registered devices. You can revoke access for individual devices here.",
+  "devices.loading": "Loading devices…",
+  "devices.mobile_tokens_description": "These tokens were created when you logged in via the mobile app or scanned a QR code. Revoking a token will sign the device out.",
+  "devices.mobile_tokens_heading": "Mobile App Tokens",
+  "devices.no_devices": "No registered devices",
+  "devices.no_devices_help": "Install the DocuElevate mobile app and log in to register a device for push notifications.",
+  "devices.no_mobile_tokens": "No mobile app tokens",
+  "devices.no_mobile_tokens_help": "Log in via the mobile app or scan a QR code to create a mobile token.",
+  "devices.page_title": "Devices – DocuElevate",
+  "devices.qr_login_cta": "Connect a new device via QR code",
+  "devices.registered_devices_description": "Devices registered for push notifications from the DocuElevate mobile app.",
+  "devices.registered_devices_heading": "Registered Devices",
+  "devices.revoke_token": "Revoke",
+  "devices.status_active": "Active",
+  "devices.status_inactive": "Inactive",
+  "devices.status_revoked": "Revoked",
+  "devices.token_revoked_success": "Device token revoked successfully.",
   "duplicates.file_id_label": "File ID",
   "duplicates.file_id_placeholder": "e.g. 42",
   "duplicates.find_btn": "Find",
@@ -1152,6 +1183,7 @@
   "nav.dark_mode": "Dark Mode",
   "nav.dashboard": "Dashboard",
   "nav.developer_docs": "Developer Docs",
+  "nav.devices": "Devices",
   "nav.duplicates": "Duplicates",
   "nav.file_manager": "File Manager",
   "nav.files": "Files",
@@ -1452,6 +1484,20 @@
   "profile.theme_system": "System Default",
   "profile.update_password": "Update Password",
   "profile.updating": "Updating…",
+  "qr_login.claimed_device": "Device: {device_name}",
+  "qr_login.claimed_message": "QR code login successful! Your mobile device is now connected.",
+  "qr_login.description": "Scan this QR code with the DocuElevate mobile app to log in instantly.",
+  "qr_login.expired_message": "This QR code has expired. Please generate a new one.",
+  "qr_login.generate_new": "Generate New QR Code",
+  "qr_login.heading": "Mobile App QR Login",
+  "qr_login.how_it_works": "How it works",
+  "qr_login.page_title": "QR Code Login – DocuElevate",
+  "qr_login.pending_message": "Waiting for mobile app to scan…",
+  "qr_login.step_1": "Open the DocuElevate app on your phone",
+  "qr_login.step_2": "Tap \"Scan QR Code\" on the login screen",
+  "qr_login.step_3": "Point your camera at this QR code",
+  "qr_login.subtitle": "Log in to the mobile app by scanning a QR code from this page.",
+  "qr_login.time_remaining": "Expires in {seconds} seconds",
   "queue.active_tasks": "Active Tasks",
   "queue.auto_refresh_1": "Auto-refreshes every",
   "queue.auto_refresh_2": "seconds",
@@ -1513,6 +1559,25 @@
   "search.saved_label": "Saved Searches",
   "search.saved_loading": "Loading...",
   "search.title": "Search Documents",
+  "sessions.active_sessions": "Active Sessions",
+  "sessions.confirm_revoke_all": "This will log you out of all other devices and browsers, and revoke all API tokens. Continue?",
+  "sessions.confirm_revoke_one": "Are you sure you want to end this session?",
+  "sessions.current_session": "This device",
+  "sessions.device_info": "Device",
+  "sessions.expires": "Expires",
+  "sessions.ip_address": "IP Address",
+  "sessions.last_active": "Last active",
+  "sessions.log_off_everywhere": "Log Off All Other Sessions",
+  "sessions.log_off_everywhere_desc": "End all other browser sessions and revoke all API tokens. Your current session will remain active.",
+  "sessions.no_other_sessions": "No other active sessions found.",
+  "sessions.qr_login_link": "Log in on mobile via QR code",
+  "sessions.revoke": "End Session",
+  "sessions.revoked_all_success": "All other sessions have been ended.",
+  "sessions.revoked_success": "Session ended successfully.",
+  "sessions.security_heading": "Security & Sessions",
+  "sessions.security_subtitle": "Manage your active sessions across devices and browsers.",
+  "sessions.session_lifetime": "Session lifetime: {days} days",
+  "sessions.started": "Started",
   "settings.audit_log_btn": "Audit Log",
   "settings.autocomplete_hint": "Type to search known values, or enter any custom value.",
   "settings.autocomplete_no_matches": "No matches — you can still type a custom value",