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/.env.example

@@ -2,7 +2,7 @@
 #
 #   cp .env.example .env
 
-# Container hostname.
+# Container hostname, also passed in as HOST -- the name zsh's prompt shows.
 SERVICE_HOSTNAME=code-server
 
 # Web UI login password. Required.

code-server/README.md

@@ -149,7 +149,7 @@ sdk install java
 | --- | --- |
 | `PASSWORD` | Web UI login. Required. |
 | `GIT_NAME` / `GIT_EMAIL` | Git author and committer identity |
-| `SERVICE_HOSTNAME` | Container hostname |
+| `SERVICE_HOSTNAME` | Container hostname, and the name the shell prompt shows (also passed as `HOST`) |
 | `CODE_SERVER_APP_NAME` | Optional. Name in the title bar and welcome page; defaults to `code-server`. |
 
 Generate a password with `openssl rand -base64 24`.
@@ -161,6 +161,13 @@ can only read from inside the container.
 The `coder` user has passwordless `sudo`, as the image sets it up. Anyone who
 can log in to the editor is root in the container.
 
+`SERVICE_HOSTNAME` is used twice: as the container's `hostname:` and as the
+`HOST` variable inside it. Coolify injects `HOST=0.0.0.0` into every compose
+app, and zsh seeds `$HOST` and the `%m`/`%M` prompt escapes from that variable
+rather than calling `gethostname()`, so a zsh prompt reads `0`. code-server
+itself never reads `HOST`; it binds through `--bind-addr`. bash is unaffected;
+its `\h` uses the real hostname.
+
 ## Docker access
 
 The host's Docker socket is bind-mounted at `/var/run/docker.sock`. The image

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'