Make webtools host port configurable via WEBTOOLS_PORT

Port 80 on the host isn't always free (e.g. another service already bound
to it), so let .env override it like the game server ports already do.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -31,7 +31,7 @@ That brings up:
 | `loginserver` | `ross-loginserver-1` | `29000` | Account login |
 | `charserver` | `ross-charserver-1` | `29100` | Character select/create/delete |
 | `worldserver` | `ross-worldserver-1` | `29200` | The actual game world |
-| `webtools` | `ross-webtools-1` | `80` | Static GM toolbox (see below) + reverse-proxies `/admin/` |
+| `webtools` | `ross-webtools-1` | `80` (`WEBTOOLS_PORT`) | Static GM toolbox (see below) + reverse-proxies `/admin/` |
 | `webadmin` | `ross-webadmin-1` | — (behind webtools) | Account/character/server admin panel |
 
 Point a KTRose pre-evo client at `PUBLIC_HOST:29000` and log in — `LOGIN_CREATE_ACCOUNT=1` (the default) auto-creates an