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/ui/HomePage.tsx

@@ -0,0 +1,81 @@
+import { fetchAllLocations } from '@/app/lib/actions/locationActions';
+import { fetchAvailableYears } from '@/app/lib/actions/monthActions';
+import { getUserSettings } from '@/app/lib/actions/userSettingsActions';
+import { BillingLocation, YearMonth } from '@/app/lib/db-types';
+import { FC } from 'react';
+import { MonthLocationList } from '@/app/ui/MonthLocationList';
+
+export interface HomePageProps {
+  searchParams?: {
+    year?: string;
+    month?: string;
+  };
+}
+
+export const HomePage:FC<HomePageProps> = async ({ searchParams }) => {
+
+  let availableYears: number[];
+
+  // const asyncTimout = (ms:number) => new Promise(resolve => setTimeout(resolve, ms));
+  // await asyncTimout(5000);
+
+  try {
+    availableYears = await fetchAvailableYears();
+  } catch (error:any) {
+    return (
+      <main className="flex min-h-screen flex-col p-6 bg-base-300">
+        <p className="text-center text-2xl text-red-500">{error.message}</p>
+      </main>);
+  }
+
+  // if the database is in it's initial state, show the add location button for the current month
+  if(availableYears.length === 0) {
+    return (<MonthLocationList />);
+  }
+
+  const currentYear = Number(searchParams?.year) || new Date().getFullYear();
+
+  const locations = await fetchAllLocations(currentYear);
+  const userSettings = await getUserSettings();
+
+  // group locations by month
+  const months = locations.reduce((acc, location) => {
+    const {year, month} =  location.yearMonth;
+    const key = `${year}-${month}`;
+
+    const locationsInMonth = acc[key];
+
+    if(locationsInMonth) {
+      return({
+        ...acc,
+        [key]: {
+          yearMonth: location.yearMonth,
+          locations: [...locationsInMonth.locations, location],
+          unpaidTotal: locationsInMonth.unpaidTotal + location.bills.reduce((acc, bill) => !bill.paid ? acc + (bill.payedAmount ?? 0) : acc, 0),
+          payedTotal: locationsInMonth.payedTotal + location.bills.reduce((acc, bill) => bill.paid ? acc + (bill.payedAmount ?? 0) : acc, 0)
+        }
+      })
+    }
+
+    return({
+      ...acc,
+      [key]: {
+        yearMonth: location.yearMonth,
+        locations: [location],
+        unpaidTotal: location.bills.reduce((acc, bill) => !bill.paid ? acc + (bill.payedAmount ?? 0) : acc, 0),
+        payedTotal: location.bills.reduce((acc, bill) => bill.paid ? acc + (bill.payedAmount ?? 0) : acc, 0)
+      }
+    });
+  }, {} as {[key:string]:{
+    yearMonth: YearMonth,
+    locations: BillingLocation[],
+    unpaidTotal: number,
+    payedTotal: number
+  } });
+
+ return (
+    <MonthLocationList availableYears={availableYears} months={months} userSettings={userSettings} />
+  );
+}
+
+export default HomePage;