feat: Add data-entry-app for fiscal receipts with approval workflow

New application for entering fiscal receipts (bonuri fiscale) with:

Backend (FastAPI + SQLModel + Alembic):
- Receipt, ReceiptAttachment, AccountingEntry models
- CRUD operations with async SQLite database
- Workflow: DRAFT → PENDING_REVIEW → APPROVED/REJECTED
- Auto-generation of accounting entries with VAT calculation
- File upload support (images, PDFs)
- Predefined expense types (Fuel, Materials, Office, etc.)
- Nomenclature service for partners, accounts, cash registers

Frontend (Vue.js 3 + PrimeVue + Pinia):
- ReceiptsListView with filters and stats
- ReceiptCreateView with image upload
- ReceiptDetailView with accounting entries
- ReceiptApprovalView for accountant approval

Documentation:
- REQUIREMENTS.md with functional specifications
- ARCHITECTURE.md with technical decisions
- CLAUDE.md for AI assistant guidance

Phase 1 MVP uses SQLite, prepared for Oracle integration in Phase 2.

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

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

data-entry-app/backend/app/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")