feat: Migrate to ultrathin monolith architecture

Consolidate 3 separate applications (reports-app, data-entry-app, telegram-bot) into a unified
architecture with single backend and frontend:

Backend Changes:
- Unified FastAPI backend at backend/ with modular structure
- Modules: reports, data_entry, telegram in backend/modules/
- Centralized config.py and main.py with all routers registered
- Single worker mode (--workers 1) for Telegram bot compatibility
- Shared Oracle connection pool and JWT authentication
- Unified requirements.txt and environment configuration

Frontend Changes:
- Single Vue.js SPA with module-based routing
- Unified frontend at src/ with modules in src/modules/{reports,data-entry}/
- Shared components and stores in src/shared/
- Error boundaries for module isolation
- Dual API proxy in Vite for module communication

Infrastructure:
- New unified startup scripts: start-prod.sh, start-test.sh, start-backend.sh
- Environment templates: .env.dev.example, .env.test.example, .env.prod.example
- Updated deployment scripts for Windows IIS
- Simplified SSH tunnel management

Documentation:
- Comprehensive CLAUDE.md with architecture overview
- Module-specific docs in docs/{data-entry,telegram}/
- Architecture decision records in docs/ARCHITECTURE-DECISIONS.md
- Deployment guides consolidated in deployment/windows/docs/

This migration reduces complexity, improves maintainability, and enables easier
deployment while maintaining all existing functionality.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

backend/modules/data_entry/services/__init__.py

@@ -0,0 +1,11 @@
+# Business logic services
+from .receipt_service import ReceiptService
+from .nomenclature_service import NomenclatureService
+from .expense_types import EXPENSE_TYPES, ExpenseType
+
+__all__ = [
+    "ReceiptService",
+    "NomenclatureService",
+    "EXPENSE_TYPES",
+    "ExpenseType",
+]