Spell the API host as api.${DOMAIN} in the worker and login examples

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013GAeg4Jo6xjZzjwy9QDWMQ

docs/code/cli.md

@@ -231,7 +231,7 @@ agent's own parser: it is the same program `fluksio-worker` installs, so the
 two are interchangeable:
 
 ```sh
-fluksio worker --url wss://api.fluksio.com/api/v1/workers/attach \
+fluksio worker --url wss://api.${DOMAIN}/api/v1/workers/attach \
                --token "$FLUKSIO_WORKER_TOKEN" --labels gpu
 ```
 
@@ -246,7 +246,7 @@ which boots one inside the command instead.
 ### `fluksio login`
 
 ```sh
-fluksio login --url https://api.fluksio.com
+fluksio login --url https://api.${DOMAIN}
 ```
 
 For an engine somewhere *else*. One you started yourself needs no login: