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/i18n.ts

@@ -0,0 +1,30 @@
+import {notFound} from 'next/navigation';
+import {getRequestConfig} from 'next-intl/server';
+import { Formats, TranslationValues } from 'next-intl';
+ 
+// Can be imported from a shared config
+export const locales = ['en', 'hr'];
+
+export const localeNames:Record<string,string> = {
+  en: '🇬🇧 En',
+  hr: '🇭🇷 Hr'
+};
+
+export const defaultLocale = 'hr';
+
+/** Templating function type as returned by `useTemplate` and `getTranslations` */
+export type IntlTemplateFn =
+  // this function type if returned by `useTransations`
+  (<TargetKey extends any>(key: TargetKey, values?: TranslationValues | undefined, formats?: Partial<Formats> | undefined) => string) |
+  // this functon type if returned by `getTranslations`
+  (<TargetKey extends any>(key: [TargetKey] extends [never] ? string : TargetKey, values?: TranslationValues | undefined, formats?: Partial<Formats> | undefined) => string);
+
+
+export default getRequestConfig(async ({locale}) => {
+  // Validate that the incoming `locale` parameter is valid
+  if (!locales.includes(locale as any)) notFound();
+ 
+  return {
+    messages: (await import(`../messages/${locale}.json`)).default
+  };
+});