Add ENTRY_VOID movement type and integrate balance entry creation in invoice processing

- Introduced a new movement type 'ENTRY_VOID' to handle invoice reversals, ensuring net balance remains zero.
- Updated the FaLineItem DTOs to replace 'download' with 'discharge' for consistency.
- Implemented balance entry creation in the invoice processing and reverting workflows, enhancing inventory management.
- Adjusted progress tracking messages to reflect the new balance entry generation steps.

backend/api/v1/modules/a24/balance_movements/models.py

@@ -74,6 +74,12 @@ class MovementType(str, Enum):
     EXPIRATION = "expiration"            # Balance cancelled due to deadline
     REGIME_CHANGE_OUT = "regime_chg_out" # Eg. temporary → definitive (exit side)
 
+    # ── Reversal (annuls a prior ENTRY — used when un-processing an invoice) ─
+    # Inserting ENTRY_VOID with the same quantity as the original ENTRY leaves
+    # the net balance at zero, preventing any further discharges against that
+    # lot. A fresh ENTRY is created when the invoice is re-processed.
+    ENTRY_VOID = "entry_void"
+
 
 # Which movement types reduce the balance (sign = -1)
 NEGATIVE_MOVEMENTS = {
@@ -85,6 +91,7 @@ NEGATIVE_MOVEMENTS = {
     MovementType.TRANSFER_OUT,
     MovementType.EXPIRATION,
     MovementType.REGIME_CHANGE_OUT,
+    MovementType.ENTRY_VOID,
 }
 
 # Which types count toward "used" (CANTUSADA in Anexo 24 report)

backend/api/v1/modules/a24/fa/fa_item_lines/dto.py

@@ -56,7 +56,7 @@ class FaLineItemCreateDTO(BaseModel):
     subitem_number: Optional[int] = Field(0, description="Número de subpartida")
 
     # Special flags
-    download: Optional[bool] = Field(None, description="Indicador de descarga")
+    discharge: Optional[bool] = Field(None, description="Indicador de descarga")
     own_equipment: Optional[bool] = Field(None, description="Equipo propio")
     omit_annex31: Optional[bool] = Field(None, description="Omitir en Anexo 31")
 
@@ -108,7 +108,7 @@ class FaLineItemUpdateDTO(BaseModel):
     subitem_number: Optional[int] = Field(None, description="Número de subpartida")
 
     # Special flags
-    download: Optional[bool] = Field(None, description="Indicador de descarga")
+    discharge: Optional[bool] = Field(None, description="Indicador de descarga")
     own_equipment: Optional[bool] = Field(None, description="Equipo propio")
     omit_annex31: Optional[bool] = Field(None, description="Omitir en Anexo 31")
 
@@ -156,7 +156,7 @@ class FaLineItemResponseDTO(BaseModel):
     subitem_number: Optional[int] = Field(None, description="Número de subpartida")
 
     # Special flags
-    download: Optional[bool] = Field(None, description="Indicador de descarga")
+    discharge: Optional[bool] = Field(None, description="Indicador de descarga")
     own_equipment: Optional[bool] = Field(None, description="Equipo propio")
     omit_annex31: Optional[bool] = Field(None, description="Omitir en Anexo 31")