fix: add APP_VERSION fallback and HOST bind address env var (#952 #953) (#955)

* fix: add APP_VERSION fallback and HOST bind env var (#952 #953)

- Read package.json version when APP_VERSION env var is absent so the
  startup banner shows the correct version for source/Proxmox installs
- Add HOST env var to control the HTTP bind address; only applied when
  set so Docker deployments are unaffected (bind-all-interfaces default)
- Parse PORT as Number() so malformed values like '10.0.0.72:3001' fall
  back to 3001 instead of silently misbehaving
- Document HOST in .env.example, Environment-Variables wiki, and
  Install-Proxmox wiki with explicit warnings against using it in Docker

* fix: correct package.json path in APP_VERSION fallback

index.ts sits at server/src/ — one level up reaches server/package.json,
not two (../../ overshot to the repo root where no package.json exists).

wiki/Environment-Variables.md

@@ -16,6 +16,7 @@ Complete reference for all environment variables TREK reads.
 | Variable | Description | Default |
 |---|---|---|
 | `PORT` | Server port | `3000` |
+| `HOST` | Bind address for the HTTP server (e.g. `127.0.0.1`, `10.0.0.72`). **Source / Proxmox installs only** — do not set this in Docker or any containerized deployment. See note below. | all interfaces |
 | `NODE_ENV` | Environment (`production` / `development`) | `production` |
 | `ENCRYPTION_KEY` | At-rest encryption key — see resolution order below | auto |
 | `TZ` | Timezone for logs, reminders, and cron jobs (e.g. `Europe/Berlin`) | `UTC` |
@@ -25,6 +26,22 @@ Complete reference for all environment variables TREK reads.
 | `ALLOW_INTERNAL_NETWORK` | Allow outbound requests to private/RFC-1918 IPs. Set `true` if Immich or other integrated services are on your local network. Loopback (`127.x`) and link-local (`169.254.x`) addresses remain blocked regardless. | `false` |
 | `APP_URL` | Public base URL (e.g. `https://trek.example.com`). Required when OIDC is enabled — must match the redirect URI registered with your IdP. Also used as the base URL for email notification links. | — |
 
+### `HOST` — Source and Proxmox installs only
+
+By default TREK binds to all network interfaces (`0.0.0.0`), which is the correct behaviour inside a container because Docker handles port exposure at the host level. Setting `HOST` overrides the bind address at the Node.js level.
+
+**When to use it:** only when running TREK directly on a host (git sources or the [Proxmox community script](Install-Proxmox)) and you need to restrict which interface the server listens on — for example, to expose TREK only on a LAN interface while keeping it off the public-facing one.
+
+**Never set `HOST` in Docker, Docker Compose, Helm, or Unraid deployments.** Use Docker's `-p <host-ip>:<host-port>:<container-port>` syntax or your orchestrator's port binding instead.
+
+```
+# .env — source / Proxmox installs only
+HOST=10.0.0.72   # bind only on this LAN interface
+PORT=3001
+```
+
+When `HOST` is set, the startup banner includes a `Host:` line confirming the bound address.
+
 ### `ENCRYPTION_KEY` — Resolution Order
 
 `server/src/config.ts` resolves the encryption key in this order:

wiki/Install-Proxmox.md

@@ -78,6 +78,17 @@ The environment file is located at `/opt/trek/server/.env` inside the container.
 systemctl restart trek
 ```
 
+### Binding to a specific network interface
+
+If your Proxmox host has multiple network interfaces and you want TREK to listen on only one of them, set the `HOST` variable in `/opt/trek/server/.env`:
+
+```
+HOST=10.0.0.72   # bind only on this LAN interface
+PORT=3001
+```
+
+> **Note:** `HOST` is only relevant for source-based and Proxmox installs. Do not use it in Docker or any containerised deployment.
+
 See [Environment-Variables](Environment-Variables) for the full variable reference.
 
 ## Updating