refactor: convert repository to monorepo with npm workspaces

Restructured the repository into a monorepo to better organize application code
and maintenance scripts.

## Workspace Structure
- web-app: Next.js application (all app code moved from root)
- housekeeping: Database backup and maintenance scripts

## Key Changes
- Moved all application code to web-app/ using git mv
- Moved database scripts to housekeeping/ workspace
- Updated Dockerfile for monorepo build process
- Updated docker-compose files (volume paths: ./web-app/etc/hosts/)
- Updated .gitignore for workspace-level node_modules
- Updated documentation (README.md, CLAUDE.md, CHANGELOG.md)

## Migration Impact
- Root package.json now manages workspaces
- Build commands delegate to web-app workspace
- All file history preserved via git mv
- Docker build process updated for workspace structure

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

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

web-app/app/[locale]/home/account/LogoutButton.tsx

@@ -0,0 +1,20 @@
+"use client";
+
+import { FC } from 'react';
+import LogoutIcon from "@mui/icons-material/Logout";
+import { signOut } from 'next-auth/react';
+import { useLocale, useTranslations } from 'next-intl';
+import { Button } from '@/app/ui/button';
+
+export const LogoutButton: FC = () => {
+    const t = useTranslations('account-page');
+    const locale = useLocale();
+
+    const handleLogout = () => {
+        signOut({ callbackUrl: `/${locale}/` });
+    };
+
+    return (
+        <button className='btn btn-neutral' onClick={handleLogout}><LogoutIcon className='text-red-400' /> {t('logout-button-label')}</button>
+    )
+}