feat(crm): módulo Tarifario — modelos, CRUD, import Excel y motor de costeo

- Tablas rate_sheets/lanes/breaks/charges (esquema crm) + migración con down().
- Catálogos nuevos: modo_tarifario, unidad_tarifa, concepto_cargo.
- CRUD de tarifarios y rutas; descarga de plantilla Excel por modo; import con
  vista previa y validación; alta directa desde Excel.
- Motor de costeo /rate-quote: aéreo (peso facturable + quiebres + optimización),
  marítimo FCL (por contenedor), LCL (W/M) y terrestre; suma cargos adicionales.

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

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

@@ -0,0 +1,148 @@
+"""Schemas del módulo Tarifario."""
+
+from datetime import date, datetime
+from decimal import Decimal
+
+from pydantic import BaseModel, ConfigDict, Field
+
+
+# ---------- Quiebres y cargos ----------
+class RateBreakDTO(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+    from_qty: Decimal = Field(0)
+    rate: Decimal = Field(0)
+
+
+class RateChargeDTO(BaseModel):
+    model_config = ConfigDict(from_attributes=True)
+    concept: str = Field(..., max_length=60)
+    charge_type: str = Field("fijo", max_length=20)
+    value: Decimal | None = None
+    condition: str | None = None
+
+
+# ---------- Rutas ----------
+class RateLaneBase(BaseModel):
+    origin: str | None = Field(None, max_length=20)
+    destination: str | None = Field(None, max_length=20)
+    region: str | None = Field(None, max_length=60)
+    equipment_type: str | None = Field(None, max_length=20)
+    rate_unit: str | None = Field(None, max_length=20)
+    min_charge: Decimal | None = None
+    flat_rate: Decimal | None = None
+    transit_days: int | None = None
+    notes: str | None = None
+
+
+class RateLaneCreate(RateLaneBase):
+    breaks: list[RateBreakDTO] = Field(default_factory=list)
+
+
+class RateLaneUpdate(RateLaneBase):
+    breaks: list[RateBreakDTO] | None = None
+
+
+class RateLaneResponse(RateLaneBase):
+    model_config = ConfigDict(from_attributes=True)
+    id: int
+    rate_sheet_id: int
+    breaks: list[RateBreakDTO] = Field(default_factory=list)
+
+
+# ---------- Tarifario (cabecera) ----------
+class RateSheetBase(BaseModel):
+    supplier_id: int | None = None
+    mode: str = Field(..., max_length=20)
+    name: str = Field(..., min_length=1, max_length=255)
+    currency: str | None = Field("USD", max_length=3)
+    valid_from: date | None = None
+    valid_to: date | None = None
+    default_origin: str | None = Field(None, max_length=20)
+    status: str = Field("borrador", max_length=20)
+    notes: str | None = None
+
+
+class RateSheetCreate(RateSheetBase):
+    pass
+
+
+class RateSheetUpdate(BaseModel):
+    supplier_id: int | None = None
+    mode: str | None = Field(None, max_length=20)
+    name: str | None = Field(None, max_length=255)
+    currency: str | None = Field(None, max_length=3)
+    valid_from: date | None = None
+    valid_to: date | None = None
+    default_origin: str | None = Field(None, max_length=20)
+    status: str | None = Field(None, max_length=20)
+    notes: str | None = None
+
+
+class RateSheetResponse(RateSheetBase):
+    model_config = ConfigDict(from_attributes=True)
+    id: int
+    tenant_id: int
+    company_id: int
+    source_file: str | None = None
+    created_by: str | None = None
+    updated_by: str | None = None
+    created_at: datetime
+    updated_at: datetime
+    lane_count: int | None = None
+
+
+# ---------- Importación ----------
+class ImportPreviewRow(BaseModel):
+    row: int
+    data: dict
+    ok: bool
+    warnings: list[str] = Field(default_factory=list)
+    errors: list[str] = Field(default_factory=list)
+
+
+class ImportPreview(BaseModel):
+    mode: str
+    total: int
+    valid: int
+    rows: list[ImportPreviewRow]
+    columns: list[str]
+
+
+class ImportConfirm(RateSheetCreate):
+    lanes: list[RateLaneCreate]
+
+
+# ---------- Costeo ----------
+class CostRequest(BaseModel):
+    mode: str
+    origin: str | None = None
+    destination: str | None = None
+    on_date: date | None = None
+    gross_weight_kg: Decimal | None = None
+    volume_m3: Decimal | None = None
+    equipment_type: str | None = None
+    quantity: int = 1
+    dangerous: bool = False
+
+
+class CostChargeLine(BaseModel):
+    concept: str
+    amount: Decimal
+
+
+class CostOption(BaseModel):
+    rate_sheet_id: int
+    rate_sheet_name: str
+    supplier_id: int | None
+    currency: str | None
+    chargeable: Decimal | None = None  # peso/wm facturable usado
+    base_cost: Decimal
+    charges: list[CostChargeLine] = Field(default_factory=list)
+    total_cost: Decimal
+    transit_days: int | None = None
+    detail: str | None = None
+
+
+class CostResult(BaseModel):
+    request: CostRequest
+    options: list[CostOption]