feat(docker): guided first run for the Compose deployment

A new Docker install was: clone (undocumented), copy .env.example by hand,
fix an Unraid data path and a Perth time zone, replace `changeme`, run the
start script, and then guess when the server was up. Start-Codeman.sh now
does all of it from a fresh clone:

- Preflight names the fix for a missing docker CLI, a missing or too-old
  Compose plugin (config --environment needs 2.27.2, docker/compose#11891),
  and an unreachable daemon (docker group, never sudo).
- With no docker/.env, it asks three questions (data folder, port,
  password; Enter takes each default: ~/codeman-docker, 3000 or the next
  free port, a generated password) and writes docker/.env FROM the example,
  so every key the updater's diffRequiredEnvKeys expects is present. Mode
  0600, host time zone, values Compose would interpolate single-quoted.
  Refuses $HOME, ~/.codeman (a native install's state dir) and anything
  inside the checkout (the image build context). --yes / no TTY take the
  defaults, --setup-only stops after writing the file. An existing .env is
  never edited, and root never runs the setup (Unraid keeps the hand route).
- After `up`, it waits until the server answers (docker exec probe, crash
  loop caught by the restart count) and prints the URL, the LAN URL, the
  generated password and the logs/stop commands; --no-wait skips the wait.
- `changeme` is refused before anything starts (the container publishes on
  every interface and holds the Docker socket); Update-Codeman.sh checks it
  before its build and down so the stack is never left stopped.
- Compose settings are read with ONE config --environment call, with its
  error reported, instead of three silent ones.

docker-compose.yaml and server.Dockerfile are untouched (their hashes gate
the in-app updater), and .env.example changes values and comments only.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/docker-compose.md

@@ -12,14 +12,25 @@ It can also include the GitHub CLI (`gh`) and the Azure CLI (`az`) with the `azu
 
 ## Prerequisites
 
-- Docker Engine or Docker Desktop with Docker Compose v2
-- A reachable Docker daemon
+- Docker Engine or Docker Desktop with the Docker Compose v2 plugin, version 2.27.2 or newer
+- A reachable Docker daemon, usable by your account without sudo (on Linux, membership of the `docker` group)
 
 The application container mounts the Docker daemon socket so Codeman can create and manage its isolated Docker cases. Treat anyone who can administer this Compose project as having Docker-host-equivalent access.
 
 ## Start
 
-Copy the environment template, set a strong password, and confirm `CODEMAN_APPDATA_PATH`. The example maps `/mnt/user/appdata/codeman` on the host to `/home/${CODEMAN_RUNTIME_USER}` in the container, preserving Codeman state and CLI credentials outside Docker-managed volumes.
+On Linux, clone the repository and run the start script:
+
+```sh
+git clone https://github.com/Ark0N/Codeman.git && cd Codeman
+bash docker/Start-Codeman.sh
+```
+
+The first run checks Docker, Compose and the daemon, then asks for a data folder (default `~/codeman-docker`), a port (default 3000, or the next free one) and a password (Enter generates one and prints it once). It writes `docker/.env` from `docker/.env.example`, builds the image, starts the container and waits until Codeman answers, then prints the URL and how to sign in. `--yes` takes every default without asking, and `--setup-only` writes `docker/.env` and stops so it can be reviewed first. The full description, including the options, is the Start section of the [Docker deployment guide](../docker/README.md#start).
+
+The data folder is mounted at `/home/${CODEMAN_RUNTIME_USER}` in the container, so Codeman state and CLI credentials stay on the host outside Docker-managed volumes. On every start the script determines `PUID` and `PGID` from the owner of that folder, and `DOCKER_SOCKET_GID` from the configured Docker socket, before invoking Compose. A root-owned data folder is rejected so the runtime account cannot become UID 0.
+
+To write `docker/.env` by hand instead (Unraid and other root-only hosts, or Compose without the script), copy the template, set a strong password, and confirm `CODEMAN_APPDATA_PATH`. The example value `/mnt/user/appdata/codeman` is an Unraid layout.
 
 ```sh
 cp docker/.env.example docker/.env
@@ -31,12 +42,6 @@ On PowerShell, use the following command instead.
 Copy-Item docker/.env.example docker/.env
 ```
 
-On Linux, run the stack with the start script. It determines `PUID` and `PGID` from the owner of `CODEMAN_APPDATA_PATH`, and `DOCKER_SOCKET_GID` from the configured Docker socket, before invoking Compose. A root-owned application-data directory is rejected so the runtime account cannot become UID 0.
-
-```sh
-bash docker/Start-Codeman.sh
-```
-
 On other platforms, run Compose directly. `PUID` and `PGID` default to `1000:1000`; set them in `docker/.env` when the application-data directory has a different owner. Naming the file with `-f` disables Compose's own discovery of `docker/docker-compose.override.yml`, so add a second `-f` for it when you keep one (see `docker/README.md`, Local customisation).
 
 ```sh
@@ -45,7 +50,7 @@ docker compose --env-file docker/.env -f docker/docker-compose.yaml up --build -
 
 The container starts as root, corrects the ownership of a bind source the daemon had to create, and drops to `PUID:PGID` with `setpriv` before Codeman starts; the capabilities that needs are declared in `docker/docker-compose.yaml` and named by the entrypoint when a compose file written elsewhere lacks them.
 
-Open `http://localhost:3000` and sign in with the username and password from `docker/.env`.
+Open the URL the script printed (`http://localhost:3000` by default) and sign in with the username and password from `docker/.env`.
 
 ## Operations
 

docs/wiki/Installation.md

@@ -141,16 +141,23 @@ See [Contributing](Contributing) for the rest of the development loop.
 ## Route D: Docker Compose
 
 Codeman itself can run in a container and spawn Docker cases as sibling containers through
-the host's Docker socket. Copy `docker/.env.example` to `docker/.env`, set
-`CODEMAN_PASSWORD`, then:
+the host's Docker socket. You need Docker with the Compose v2 plugin (2.27.2 or newer), and
+an account that can use Docker without sudo (on Linux, the `docker` group). Then, on Linux:
 
 ```bash
+git clone https://github.com/Ark0N/Codeman.git && cd Codeman
 bash docker/Start-Codeman.sh
 ```
 
+The first run asks for a data folder, a port and a password. Enter takes each default,
+including a generated password that is printed once. It then writes `docker/.env`, builds the
+image (a few minutes the first time) and ends on the URL once Codeman answers. The image
+already includes Claude Code, Codex, Gemini CLI and OpenCode: start a session and log the CLI
+in once, and the login is kept in the data folder.
+
 Run the script again after updating rather than a plain `docker compose up`, so the rebuilt
 image, the refreshed volumes and the entrypoint arrive together. The full guide, including
-storage and networking options, is
+Unraid, storage and networking options, is
 [`docker/README.md`](https://github.com/Ark0N/Codeman/blob/master/docker/README.md).
 
 ## Installing an agent CLI