Add comprehensive backend features and mobile UI improvements

Backend:
- Add 2FA authentication with TOTP support
- Add API keys management system
- Add audit logging for security events
- Add file upload/management system
- Add notifications system with preferences
- Add session management
- Add webhooks integration
- Add analytics endpoints
- Add export functionality
- Add password policy enforcement
- Add new database migrations for core tables

Frontend:
- Add module position system (top/bottom sidebar sections)
- Add search and notifications module configuration tabs
- Add mobile logo replacing hamburger menu
- Center page title absolutely when no tabs present
- Align sidebar footer toggles with navigation items
- Add lighter icon color in dark theme for mobile
- Add API keys management page
- Add notifications page with context
- Add admin analytics and audit logs pages

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/locales/en.json

@@ -10,6 +10,10 @@
     "username": "Username",
     "password": "Password",
     "email": "Email",
+    "twoFactorCode": "2FA code",
+    "twoFactorPrompt": "Enter the 6-digit code from your authenticator app (or an 8-character backup code).",
+    "verifyCode": "Verify",
+    "backToLogin": "Back to login",
     "loginTitle": "Login",
     "registerTitle": "Register",
     "alreadyHaveAccount": "Already have an account? Login",
@@ -27,6 +31,8 @@
   },
   "sidebar": {
     "dashboard": "Dashboard",
+    "search": "Search",
+    "notifications": "Notifications",
     "feature1": "Feature 1",
     "feature2": "Feature 2",
     "feature3": "Feature 3",
@@ -59,7 +65,14 @@
     "configTab": "Configuration",
     "orderSection": "Sidebar Order",
     "orderDesc": "Drag to reorder features in the sidebar",
-    "applyOrder": "Apply"
+    "applyOrder": "Apply",
+    "visibility": "Visibility",
+    "topSection": "Main Section",
+    "bottomSection": "Bottom Section",
+    "moveToTop": "Move to top",
+    "moveToBottom": "Move to bottom",
+    "noModulesTop": "No modules in this section",
+    "noModulesBottom": "No modules in this section"
   },
   "sourcesPage": {
     "title": "Sources",
@@ -306,13 +319,103 @@
     "languageDesc": "Select your preferred language",
     "english": "English",
     "italian": "Italiano",
+    "preferences": "Preferences",
+    "security": "Security",
+    "enabled": "Enabled",
+    "disabled": "Disabled",
+    "twoFactorTitle": "Two-factor authentication (2FA)",
+    "twoFactorDesc": "Protect your account with TOTP codes from an authenticator app.",
+    "enable2fa": "Enable 2FA",
+    "qrCodeAlt": "2FA QR code",
+    "secret": "Secret",
+    "verificationCode": "Verification code",
+    "verifyEnable2fa": "Verify and enable",
+    "backupCodes": "Backup codes",
+    "backupCodesDesc": "Generate new backup codes (requires a valid code).",
+    "backupCodesSaveHint": "Save these codes in a safe place. Each code can be used once to access your account if you lose your authenticator.",
+    "regenerateBackupCodes": "Regenerate backup codes",
+    "disable2fa": "Disable 2FA",
+    "disable2faDesc": "Disable two-factor authentication (requires your password and a valid code).",
+    "disable2faConfirm": "Disable",
+    "sessionsTitle": "Active sessions",
+    "sessionsDesc": "View and revoke sessions on other devices.",
+    "revokeAllOtherSessions": "Revoke all other sessions",
+    "revokeSession": "Revoke",
+    "currentSession": "Current",
+    "inactiveSession": "Inactive",
+    "sessionsEmpty": "No sessions found",
+    "unknownDevice": "Unknown device",
+    "unknownBrowser": "Unknown browser",
+    "unknownOs": "Unknown OS",
+    "lastActive": "Last active",
     "comingSoon": "User settings will be available soon...",
     "placeholderTitle": "Settings"
   },
+  "notificationsPage": {
+    "title": "Notifications",
+    "unreadOnly": "Unread only",
+    "markAllRead": "Mark all as read",
+    "deleteRead": "Delete read",
+    "markRead": "Mark as read",
+    "empty": "No notifications",
+    "loadError": "Failed to load notifications"
+  },
+  "analyticsPage": {
+    "title": "Analytics",
+    "usersTotal": "Total users",
+    "usersActive": "Active users",
+    "usersNew": "New users",
+    "sessionsActive": "Active sessions",
+    "logins24h": "Logins (24h)",
+    "failedLogins24h": "Failed (24h)",
+    "notificationsUnread": "Unread notifications",
+    "userActivity7d": "User activity (7d)",
+    "actions24h": "Actions (24h)",
+    "generatedAt": "Generated at"
+  },
+  "auditPage": {
+    "title": "Audit Log",
+    "username": "Username",
+    "action": "Action",
+    "resourceType": "Resource type",
+    "anyStatus": "Any status",
+    "statusSuccess": "Success",
+    "statusFailure": "Failure",
+    "statusPending": "Pending",
+    "statusError": "Error",
+    "empty": "No audit log entries",
+    "time": "Time",
+    "user": "User",
+    "resource": "Resource",
+    "status": "Status",
+    "ip": "IP",
+    "prev": "Prev",
+    "next": "Next",
+    "page": "Page"
+  },
+  "apiKeysPage": {
+    "title": "API Keys",
+    "createTitle": "Create API key",
+    "createDesc": "Generate an API key for external API access. The key is shown only once.",
+    "namePlaceholder": "Key name (e.g. CI, integration, script)",
+    "createButton": "Create",
+    "showOnce": "Shown once",
+    "copy": "Copy",
+    "listTitle": "Your keys",
+    "empty": "No API keys yet",
+    "name": "Name",
+    "prefix": "Prefix",
+    "status": "Status",
+    "lastUsed": "Last used",
+    "usage": "Usage",
+    "actions": "Actions",
+    "revoke": "Revoke",
+    "revoked": "Revoked"
+  },
   "feature1": {
     "title": "Feature 1",
     "subtitle": "Feature 1 management",
     "comingSoon": "Feature coming soon...",
     "management": "Feature 1 Management"
   }
-}
+}