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/crud/attachment.py

@@ -0,0 +1,140 @@
+"""CRUD operations for receipt attachments."""
+
+import os
+import uuid
+import aiofiles
+from datetime import datetime
+from pathlib import Path
+from typing import Optional, List
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from fastapi import UploadFile
+
+from app.db.models.receipt import ReceiptAttachment
+from app.config import settings
+
+
+class AttachmentCRUD:
+    """CRUD operations for ReceiptAttachment model."""
+
+    @staticmethod
+    def _generate_stored_filename(original_filename: str) -> str:
+        """Generate unique filename for storage."""
+        ext = Path(original_filename).suffix.lower()
+        return f"{uuid.uuid4()}{ext}"
+
+    @staticmethod
+    def _get_upload_path(stored_filename: str) -> Path:
+        """Get full path for storing file, organized by year/month."""
+        now = datetime.utcnow()
+        relative_path = Path(str(now.year)) / f"{now.month:02d}"
+        full_path = settings.upload_path_resolved / relative_path
+
+        # Ensure directory exists
+        full_path.mkdir(parents=True, exist_ok=True)
+
+        return relative_path / stored_filename
+
+    @staticmethod
+    async def create(
+        session: AsyncSession,
+        receipt_id: int,
+        file: UploadFile,
+    ) -> ReceiptAttachment:
+        """Create attachment by saving file and creating DB record."""
+        # Generate stored filename
+        stored_filename = AttachmentCRUD._generate_stored_filename(file.filename or "upload")
+
+        # Get relative path
+        relative_path = AttachmentCRUD._get_upload_path(stored_filename)
+
+        # Full path for saving
+        full_path = settings.upload_path_resolved / relative_path
+
+        # Read file content
+        content = await file.read()
+        file_size = len(content)
+
+        # Validate file size
+        if file_size > settings.max_upload_size_bytes:
+            raise ValueError(f"File too large. Maximum size is {settings.max_upload_size_mb}MB")
+
+        # Validate MIME type
+        mime_type = file.content_type or "application/octet-stream"
+        if mime_type not in settings.allowed_mime_types:
+            raise ValueError(f"File type not allowed: {mime_type}")
+
+        # Save file
+        async with aiofiles.open(full_path, "wb") as f:
+            await f.write(content)
+
+        # Create DB record
+        attachment = ReceiptAttachment(
+            receipt_id=receipt_id,
+            filename=file.filename or "upload",
+            stored_filename=stored_filename,
+            file_path=str(relative_path),
+            file_size=file_size,
+            mime_type=mime_type,
+        )
+
+        session.add(attachment)
+        await session.commit()
+        await session.refresh(attachment)
+
+        return attachment
+
+    @staticmethod
+    async def get_by_id(
+        session: AsyncSession,
+        attachment_id: int,
+    ) -> Optional[ReceiptAttachment]:
+        """Get attachment by ID."""
+        query = select(ReceiptAttachment).where(ReceiptAttachment.id == attachment_id)
+        result = await session.execute(query)
+        return result.scalar_one_or_none()
+
+    @staticmethod
+    async def get_by_receipt_id(
+        session: AsyncSession,
+        receipt_id: int,
+    ) -> List[ReceiptAttachment]:
+        """Get all attachments for a receipt."""
+        query = select(ReceiptAttachment).where(
+            ReceiptAttachment.receipt_id == receipt_id
+        ).order_by(ReceiptAttachment.uploaded_at.asc())
+
+        result = await session.execute(query)
+        return list(result.scalars().all())
+
+    @staticmethod
+    def get_file_path(attachment: ReceiptAttachment) -> Path:
+        """Get full file path for an attachment."""
+        return settings.upload_path_resolved / attachment.file_path
+
+    @staticmethod
+    async def delete(session: AsyncSession, attachment: ReceiptAttachment) -> bool:
+        """Delete attachment (file and DB record)."""
+        # Delete file
+        file_path = AttachmentCRUD.get_file_path(attachment)
+        if file_path.exists():
+            os.remove(file_path)
+
+        # Delete DB record
+        await session.delete(attachment)
+        await session.commit()
+
+        return True
+
+    @staticmethod
+    async def delete_all_for_receipt(session: AsyncSession, receipt_id: int) -> int:
+        """Delete all attachments for a receipt."""
+        attachments = await AttachmentCRUD.get_by_receipt_id(session, receipt_id)
+        count = 0
+
+        for attachment in attachments:
+            await AttachmentCRUD.delete(session, attachment)
+            count += 1
+
+        return count