feat(release): prepare first public preview

docs/ENVIRONMENT.md

@@ -238,6 +238,8 @@ consumer; builder values and supervisor values are not user-editable app setting
 | `PYTHONUNBUFFERED` | Image: `1` | Flush Python stdout/stderr without buffering. |
 | `MAGENT_UID` | Build argument: `1000` | Image runtime user's UID. Not a runtime environment switch; rebuilding with a different UID also requires matching volume/tmpfs ownership. |
 | `MAGENT_GID` | Build argument: `1000` | Image runtime user's GID; same ownership caveat as UID. |
+| `MAGENT_VERSION` | Build argument: `0.1.0-preview.1` | OCI image version label. Release builds set this to their public version; it does not change runtime data. |
+| `MAGENT_REVISION` | Build argument: `unknown` | OCI image source-revision label. Release builds set this to the full source commit. |
 
 ## Manual Compose and test tooling
 
@@ -249,6 +251,8 @@ verification tools, not the zero-input public Compose install.
 | `MAGENT_IMAGE` | Required by `docker-compose.hub.yml` | Explicit published image tag/digest for manual-secret installations. |
 | `MAGENT_BIND_ADDRESS` | `127.0.0.1` | Manual template frontend bind address. |
 | `MAGENT_HTTP_PORT` | `3000` | Manual template frontend host port. |
+| `MAGENT_COMPOSE_FILE` | `compose.yml` | Optional `setup.sh` Compose filename override. Use a trusted local file. |
+| `MAGENT_PROJECT_NAME` | `magent` | Optional `setup.sh` Compose project name. Keep it stable to retain the same named volume. |
 | `PYTHON_BIN` | `python3` | Interpreter used by the backend quality gate. |
 | `MAGENT_IMAGE_MAX_MB` | `350` | Container smoke-test unpacked image size budget in MiB. |
 | `MAGENT_SMOKE_MANAGED` | `false` | Test generated managed secrets when true, or synthetic manual keys when false. |