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/manifest.webmanifest

@@ -0,0 +1,41 @@
+{
+    "name": "App Režije",
+    "short_name": "Režije",
+    "icons": [
+        {
+            "src": "/icon1.png",
+            "sizes": "16x16",
+            "type": "image/png"
+        },
+        {
+            "src": "/icon2.png",
+            "sizes": "32x32",
+            "type": "image/png"
+        },
+        {
+            "src": "/icon3.png",
+            "sizes": "48x48",
+            "type": "image/png"
+        },
+        {
+            "src": "/icon4.png",
+            "sizes": "64x64",
+            "type": "image/png"
+        },
+        {
+            "src": "/icon5.png",
+            "sizes": "128x128",
+            "type": "image/png"
+        },
+        {
+            "src": "/icon6.png",
+            "sizes": "256x256",
+            "type": "image/png"
+        }
+    ],
+    "start_url": "/",
+    "scope": "/",
+    "theme_color": "#15191e",
+    "background_color": "#15191e",
+    "display": "standalone"
+}