fix: restore HOST override in zsh workspace services

Coolify injects HOST=0.0.0.0 and zsh's prompt reads $HOST instead of the
real hostname, so hostname: alone shows user@0. Set HOST=${SERVICE_HOSTNAME}
again in code-server, code-server-lsio and paseo.

code-server/compose.yml

@@ -12,6 +12,7 @@ services:
       - GIT_AUTHOR_EMAIL=${GIT_EMAIL}
       - GIT_COMMITTER_NAME=${GIT_NAME}
       - GIT_COMMITTER_EMAIL=${GIT_EMAIL}
+      - HOST=${SERVICE_HOSTNAME}
       # - CODE_SERVER_APP_NAME=${CODE_SERVER_APP_NAME:-code-server}
     volumes:
       - 'code-server-home:/home/coder'