Configure v1.6.0 display across application

- backend/app/core/config.py: Add APP_VERSION = '1.6.0' setting
- backend/app/main.py: Update health and root endpoints to show APP_VERSION
- frontend-internal/Sidebar.svelte: Add version display in sidebar footer
- frontend-client/+layout.svelte: Add version in page footer
- All endpoints now return both app_version (1.6.0) and api_version (v1)

backend/app/main.py

@@ -56,7 +56,7 @@ async def lifespan(app: FastAPI):
 app = FastAPI(
     title="ServiceManagerWeb API",
     description="Mesa de Ayuda B2B multi-tenant para Aduanasoft",
-    version=settings.API_VERSION,
+    version=settings.APP_VERSION,
     lifespan=lifespan,
     docs_url=f"/{settings.API_VERSION}/docs" if settings.ENVIRONMENT == "development" else None,
     redoc_url=f"/{settings.API_VERSION}/redoc" if settings.ENVIRONMENT == "development" else None,
@@ -163,7 +163,8 @@ async def health_check():
     return {
         "status": "healthy",
         "service": "ServiceManagerWeb API",
-        "version": settings.API_VERSION,
+        "version": settings.APP_VERSION,
+        "api_version": settings.API_VERSION,
         "environment": settings.ENVIRONMENT
     }
 
@@ -174,7 +175,8 @@ async def root():
     """Endpoint raíz con información básica."""
     return {
         "service": "ServiceManagerWeb API",
-        "version": settings.API_VERSION,
+        "version": settings.APP_VERSION,
+        "api_version": settings.API_VERSION,
         "docs": f"/{settings.API_VERSION}/docs",
         "environment": settings.ENVIRONMENT
     }