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/db/models/accounting_entry.py

@@ -0,0 +1,49 @@
+"""AccountingEntry SQLModel model for proposed accounting entries."""
+
+from datetime import datetime
+from decimal import Decimal
+from enum import Enum
+from typing import Optional, TYPE_CHECKING
+
+from sqlmodel import SQLModel, Field, Relationship
+
+if TYPE_CHECKING:
+    from .receipt import Receipt
+
+
+class EntryType(str, Enum):
+    """Type of accounting entry."""
+    DEBIT = "debit"
+    CREDIT = "credit"
+
+
+class AccountingEntry(SQLModel, table=True):
+    """Proposed accounting entry for a receipt."""
+
+    __tablename__ = "accounting_entries"
+
+    id: Optional[int] = Field(default=None, primary_key=True)
+    receipt_id: int = Field(foreign_key="receipts.id", index=True)
+
+    # Account
+    entry_type: EntryType
+    account_code: str = Field(max_length=20)  # e.g., 6022, 5311, 4426
+    account_name: Optional[str] = Field(default=None, max_length=200)  # Cache: "Cheltuieli combustibil"
+
+    # Amount
+    amount: Decimal = Field(decimal_places=2, max_digits=15)
+
+    # Analytics (optional)
+    partner_id: Optional[int] = Field(default=None)
+    cost_center_id: Optional[int] = Field(default=None)
+
+    # Entry metadata
+    is_auto_generated: bool = Field(default=True)  # True if system-generated
+    modified_by: Optional[str] = Field(default=None, max_length=100)  # Username if modified
+    modified_at: Optional[datetime] = Field(default=None)
+
+    # Order for display
+    sort_order: int = Field(default=0)
+
+    # Relationship
+    receipt: Optional["Receipt"] = Relationship(back_populates="entries")