platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-gui/api/transport.py

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+from .transport_clients import TransportClientsApiMixin
+from .transport_policy import TransportPolicyApiMixin
+from .transport_singbox import TransportSingBoxApiMixin
+
+
+class TransportApiMixin(
+    TransportClientsApiMixin,
+    TransportPolicyApiMixin,
+    TransportSingBoxApiMixin,
+):
+    """Facade mixin for transport domain API.
+
+    Kept for backward compatibility with existing `from api.transport import TransportApiMixin`
+    imports while implementation is split by subdomain.
+    """
+
+    pass