feat(crm): tarifario — editor de cargos adicionales + alta manual de rutas

- Backend: CRUD de cargos (rate_charges) por tarifario.
- Frontend: detalle del tarifario con alta manual de rutas (con editor de quiebres
  para aéreo/LCL) y sección de cargos adicionales (agregar/eliminar).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/api/v1/modules/crm/rates/dto.py

@@ -21,6 +21,32 @@ class RateChargeDTO(BaseModel):
     condition: str | None = None
 
 
+class RateChargeCreate(BaseModel):
+    concept: str = Field(..., max_length=60)
+    charge_type: str = Field("fijo", max_length=20)
+    value: Decimal | None = None
+    condition: str | None = None
+    rate_lane_id: int | None = None
+
+
+class RateChargeUpdate(BaseModel):
+    concept: str | None = Field(None, max_length=60)
+    charge_type: str | None = Field(None, max_length=20)
+    value: Decimal | None = None
+    condition: str | None = None
+
+
+class RateChargeResponse(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+    id: int
+    rate_sheet_id: int | None
+    rate_lane_id: int | None
+    concept: str
+    charge_type: str
+    value: Decimal | None
+    condition: str | None
+
+
 # ---------- Rutas ----------
 class RateLaneBase(BaseModel):
     origin: str | None = Field(None, max_length=20)