docs(auth): document local OIDC and Authentik operation

docs/install/local.md

@@ -169,6 +169,17 @@ services; retain TLS and authentication even when co-located.
 
 ## Build ThothII and thothctl
 
+The canonical local Compose smoke uses the base file plus the local profile. Keep this exact
+base+profile command available for install verification:
+
+~~~sh
+docker compose --env-file deploy/env/local.env +  -f compose.yaml -f deploy/compose.local.yaml up --build -d
+~~~
+
+After the stack is ready, configure and check authentication with the single host CLI tht; see
+the [local authentication guide](authentication-local.md). Authentication configuration is
+installation-global and is checked before workspace tests.
+
 From the repository root, macOS/Linux/WSL2 users run:
 
 ```sh