gateway: alphabetize the displayed route table

Sort routes by address in GET /gateway and 'castle gateway status' (so the
dashboard + CLI tables read alphabetically). The Caddyfile keeps its
precedence-sensitive order — only the display is sorted.

castle-api/src/castle_api/routes.py

@@ -878,6 +878,8 @@ def get_gateway() -> GatewayInfo:
         )
         for r in compute_routes(registry, config, remote or None)
     ]
+    # Caddyfile order is precedence-sensitive; the displayed table is alphabetical.
+    routes.sort(key=lambda r: r.address)
 
     return GatewayInfo(
         port=registry.node.gateway_port,