feat: Implement multi-tenancy support in middleware and security layers

- Enhanced TenantMiddleware to validate tenant information from JWT tokens.
- Added LicenseValidationMiddleware to check tenant licenses before processing requests.
- Updated security utilities to extract tenant information from tokens and validate company access.
- Introduced CompanyStore to manage active company state and handle company switching in the frontend.
- Modified API routes to include company_id in requests for better resource management.
- Improved logging and error handling throughout the middleware and API layers.
- Updated frontend components to reflect changes in company management and selection.
- Added new API route for fetching user's companies with proper authentication handling.

backend/main.py

@@ -2,6 +2,7 @@
 Anexo76 - Aplicación SaaS para gestión de comercio exterior
 Backend API con FastAPI + Keycloak + SQLAlchemy
 """
+
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 import logging
@@ -10,7 +11,7 @@ from core.config import settings
 from core.middleware import (
     TenantMiddleware,
     LicenseValidationMiddleware,
-    RequestLoggingMiddleware
+    RequestLoggingMiddleware,
 )
 from core.database import init_db
 from api.v1.router import router as api_v1_router
@@ -18,7 +19,7 @@ from api.v1.router import router as api_v1_router
 # Configurar logging
 logging.basicConfig(
     level=logging.INFO if not settings.DEBUG else logging.DEBUG,
-    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
 )
 
 logger = logging.getLogger(__name__)
@@ -33,6 +34,7 @@ app = FastAPI(
     openapi_url="/api/openapi.json" if settings.DEBUG else None,
 )
 
+
 # Inicializar la base de datos
 @app.on_event("startup")
 async def on_startup():
@@ -41,6 +43,7 @@ async def on_startup():
     init_db()
     logger.info("Base de datos inicializada correctamente.")
 
+
 # Configurar CORS
 app.add_middleware(
     CORSMiddleware,
@@ -60,6 +63,7 @@ app.add_middleware(TenantMiddleware)
 # Registrar routers
 app.include_router(api_v1_router, prefix="/api/v1")
 
+
 @app.get("/api/")
 async def root():
     """Root endpoint"""
@@ -67,14 +71,11 @@ async def root():
         "name": "Anexo76 API",
         "version": settings.APP_VERSION,
         "status": "running",
-        "docs": "/api/docs" if settings.DEBUG else "disabled in production"
+        "docs": "/api/docs" if settings.DEBUG else "disabled in production",
     }
 
 
 @app.get("/api/health")
 async def health_check():
     """Health check endpoint"""
-    return {
-        "status": "healthy",
-        "environment": settings.ENVIRONMENT
-    }
+    return {"status": "healthy", "environment": settings.ENVIRONMENT}