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>

.claude/settings.local.json

@@ -20,7 +20,10 @@
       "mcp__context7__resolve-library-id",
       "mcp__context7__get-library-docs",
       "mcp__serena__create_text_file",
-      "Bash(curl:*)"
+      "Bash(curl:*)",
+      "Bash(git mv:*)",
+      "Bash(rmdir:*)",
+      "Bash(mkdir:*)"
     ]
   },
   "enableAllProjectMcpServers": true,