chore: drop HOST overrides, move known issue to docs, tidy comments and gitignores

- Remove HOST=${SERVICE_HOSTNAME} from code-server, code-server-lsio and paseo; hostname: alone sets the name
- Move SERVICE_HOSTNAME to the top of their .env.example to match compose order
- Drop the openclaw ARM64 Chromium note from its README; docs/openclaw covers it
- List CUSTOM_USER in webtop's setup step
- Trim reasoning from diun and paseo comments
- Delete stale gitea and gitea-mirror .gitignore files
- Add TODO.md for remaining naming and README issues

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, and the name the shell prompt shows (also passed as `HOST`) |
+| `SERVICE_HOSTNAME` | Container hostname |
 | `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`.
@@ -161,13 +161,6 @@ 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