feat: Add payment methods extraction, OCR improvements, and AutoComplete fix

Backend:
- Add payment_methods and payment_mode fields to Receipt model
- Add payment method extraction (CARD/NUMERAR) with auto-suggestion logic
- Improve OCR service with TVA validation and reverse calculation
- Fix nomenclature service supplier limit (was 50, now unlimited)
- Add OCR fields migrations (ocr_raw_text, ocr_confidence, payment_mode)

Frontend:
- Fix AutoComplete to properly display supplier name after OCR
- Add payment methods display in OCR preview with suggested payment mode
- Improve ReceiptCreateView form handling and OCR data application

Database migrations:
- 20251215_add_ocr_fields_to_receipt.py
- 20251215_remove_partner_id.py
- 20251216_add_payment_mode.py

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

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

data-entry-app/backend/migrations/versions/20251215_remove_partner_id.py

@@ -0,0 +1,29 @@
+"""Remove partner_id from receipts - supplier data is text-only
+
+Revision ID: 20251215_remove_partner_id
+Revises: 20251216_payment_mode
+Create Date: 2025-12-15
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '20251215_remove_partner_id'
+down_revision: Union[str, None] = '20251216_payment_mode'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Remove partner_id column - supplier data is now text-only (partner_name, cui)."""
+    # Drop the partner_id column
+    op.drop_column('receipts', 'partner_id')
+
+
+def downgrade() -> None:
+    """Re-add partner_id column."""
+    op.add_column('receipts', sa.Column('partner_id', sa.Integer(), nullable=True))