fix: show the container hostname in the shell prompt

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().
The prompt read "0", the first dot-separated field of 0.0.0.0, even though the
container hostname itself was set correctly.

Pass the hostname in as HOST alongside the hostname: key, both from a single
SERVICE_HOSTNAME variable. Neither service reads HOST itself -- code-server
binds [::]:8443, Paseo binds PASEO_LISTEN -- so this only affects the prompt.

Not named HOSTNAME: Compose interpolation lets the deploying shell's
environment win over the .env file, and HOSTNAME is set in every container,
including the one Coolify runs in.

PASEO_LABEL is renamed to SERVICE_HOSTNAME; it was never a Paseo variable.
The example git identity is blanked out along with it.

code-server/.env.example

@@ -2,6 +2,10 @@
 #
 #   cp .env.example .env
 
+# Container hostname, also passed in as HOST -- the name zsh's prompt shows.
+# Not named HOSTNAME: the deploying shell's own HOSTNAME would override it.
+SERVICE_HOSTNAME=code-server
+
 # Web UI login password. MUST NOT be blank -- the LinuxServer image serves
 # code-server without authentication when PASSWORD is empty.
 # Also used for SUDO_PASSWORD inside the container.

code-server/README.md

@@ -25,11 +25,25 @@ because this is a single-user dev box.
 
 | Variable | Purpose |
 | --- | --- |
+| `SERVICE_HOSTNAME` | Container hostname, and the name the shell prompt shows. |
 | `PASSWORD` | Web UI login, also the in-container sudo password. **A blank value disables authentication entirely.** |
 | `GIT_NAME` / `GIT_EMAIL` | Git author and committer identity |
 
 Generate a password with `openssl rand -base64 24`.
 
+`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 the prompt reads `0`, the first
+dot-separated field of `0.0.0.0`. code-server itself never reads `HOST` -- it
+binds `[::]:8443` -- so overriding it only affects the prompt. bash is
+unaffected; its `\h` uses the real hostname.
+
+It is not called `HOSTNAME`, the obvious name, because Compose interpolation
+lets the deploying shell's environment win over the `.env` file, and `HOSTNAME`
+is set in every container -- including the one Coolify itself runs in. The
+container would silently take Coolify's hostname instead of this value.
+
 ## Networking
 
 Listens on `8443`. No ports are published — point the domain at that port in

code-server/compose.yml

@@ -1,11 +1,13 @@
 services:
   code-server:
     image: 'lscr.io/linuxserver/code-server:latest'
-    hostname: miti99-cs
+    hostname: ${SERVICE_HOSTNAME}
     environment:
       - PUID=1000
       - PGID=1000
       - TZ=Asia/Ho_Chi_Minh
+      # Hostname zsh's prompt reads, overriding the one Coolify injects.
+      - HOST=${SERVICE_HOSTNAME}
       - DEFAULT_WORKSPACE=/config/workspace
       - PWA_APPNAME=code-server
       - 'DOCKER_MODS=linuxserver/mods:universal-package-install|linuxserver/mods:universal-docker|linuxserver/mods:code-server-golang|linuxserver/mods:code-server-nodejs|linuxserver/mods:code-server-npmglobal|linuxserver/mods:code-server-pnpm|linuxserver/mods:code-server-python3|linuxserver/mods:code-server-zsh'