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/client_secret.apps.googleusercontent.com.json

@@ -0,0 +1,16 @@
+{
+    "web": {
+        "client_id": "355397364527-adjrokm6hromcaaar0qfhk050mfr35ou.apps.googleusercontent.com",
+        "project_id": "evidencija-rezija",
+        "auth_uri": "https://accounts.google.com/o/oauth2/auth",
+        "token_uri": "https://oauth2.googleapis.com/token",
+        "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
+        "client_secret": "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",
+        "redirect_uris": [
+            "http://localhost:3000/api/auth/callback/google"
+        ],
+        "javascript_origins": [
+            "http://localhost:3000"
+        ]
+    }
+}