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/lib/auth.ts

@@ -0,0 +1,117 @@
+import NextAuth, { NextAuthConfig } from 'next-auth';
+import GoogleProvider from 'next-auth/providers/google';
+// import LinkedinProvider from 'next-auth/providers/linkedin';
+import { Session } from 'next-auth';
+import { AuthenticatedUser } from './types/next-auth';
+import { defaultLocale } from '../i18n';
+
+export const myAuth = () => {
+   // Use mock authentication in development when enabled via environment variable
+   if (process.env.NODE_ENV === 'development' && process.env.USE_MOCK_AUTH === 'true') {
+      const session: Session = {
+         user: {
+            id: process.env.MOCK_USER_ID || "109754742613069927799",
+            name: process.env.MOCK_USER_NAME || "Nikola Derežić",
+         },
+         expires: "123",
+      };
+      
+      return Promise.resolve(session);
+   }
+
+   return auth();
+}
+
+export const authConfig: NextAuthConfig = {
+   callbacks: {
+      // method verifies if the user is logged in or not
+      // -> is called by Next-Auth when the midleware calls the `auth` method (exported below)
+      authorized({ auth, request: { nextUrl } }) {
+         const isLoggedIn = !!auth?.user;
+         return (isLoggedIn);
+      },
+      // method is called when the user is not logged in
+      // this is a hack which takes user ID and assigns it temporaty to the token, which is then used to extend Session.user
+      // see: https://stackoverflow.com/questions/70409219/get-user-id-from-session-in-next-auth-client
+      jwt({ token, account, user }) {
+         if (account) {
+            // console.log("(JWT) account:", account);
+            // console.log("(JWT) user:", user);
+           token.accessToken = account.access_token;
+           // attach Google account ID to the token
+           token.piggyback_providerAccountId = account.providerAccountId;
+           
+         }
+         return token
+      },
+      // method is called after the JWT token is created
+      // this is a hack which takes user ID temporaty assigned to the token and assigns it to the Session.user
+      // see: https://stackoverflow.com/questions/70409219/get-user-id-from-session-in-next-auth-client
+      async session({ session, token }:{ session:Session, token:any }) {
+         if(session.user && token) {
+            // assign Google account ID from the token to the Session user ID
+            session.user.id = token.piggyback_providerAccountId;
+//            console.log("(SESSION) token:", token);
+         }
+         return session;
+       },
+   },
+   providers: [
+      GoogleProvider({
+         clientId: process.env.GOOGLE_ID,
+         clientSecret: process.env.GOOGLE_SECRET,
+      }),
+      // // config based on https://github.com/nextauthjs/next-auth/issues/8831
+      // LinkedinProvider({
+      //    clientId: process.env.LINKEDIN_ID,
+      //    clientSecret: process.env.LINKEDIN_SECRET,
+      //    authorization: { params: { scope: 'email openid' } },
+      //    issuer: 'https://www.linkedin.com',
+      //    jwks_endpoint: "https://www.linkedin.com/oauth/openid/jwks",
+      //    async profile(profile) {
+      //        return {
+      //            id: profile.sub,
+      //            name: profile.name,
+      //            firstname: profile.given_name,
+      //            lastname: profile.family_name,
+      //            email: profile.email
+      //        }
+      //    },
+      // })
+   ],
+   secret: process.env.AUTH_SECRET,
+   trustHost: true, // needs to be set to false for the NextJS to work behing Traefik
+   session: {
+      // Use JSON Web Tokens for session instead of database sessions.
+      // This option can be used with or without a database for users/accounts.
+      // Note: `jwt` is automatically set to `true` if no database is specified.
+      strategy: 'jwt'
+   },
+   pages: {
+      signIn: `/${defaultLocale}`,
+   },
+};
+
+export const { auth, handlers: { GET, POST } } = NextAuth(authConfig);
+
+export type AuthErrorMessage = {
+   message: string,
+   errors: {
+      message: string,
+   }
+}
+
+export const isAuthErrorMessage = (obj: any): obj is AuthErrorMessage => {
+   return (obj.message && obj.errors && obj.errors.message);
+}
+
+export const withUser = <T, A extends any[]>(fn: (user: AuthenticatedUser, ...args:A) => Promise<T>) => async (...args:A) => {
+   const session = await myAuth();
+
+   if(!session) {
+      throw new Error("Not authenticated")
+   }
+   const { user } = session;
+
+   return(fn(user, ...args));
+}