fix(doc):update the document for the docker configuration

backend/docs/CONFIGURATION.md

@@ -434,6 +434,76 @@ DeerFlow searches for configuration in this order:
 3. `config.yaml` under `DEER_FLOW_PROJECT_ROOT`, or under the current working directory when `DEER_FLOW_PROJECT_ROOT` is unset
 4. Legacy backend/repository-root locations for monorepo compatibility
 
+## Security Notes
+### Sandbox Isolation and the Docker Socket (DooD)
+
+DeerFlow executes agent-generated shell/code through a configurable sandbox
+(`sandbox.use` in `config.yaml`). The isolation guarantees differ by mode, and
+one mode requires mounting the host Docker socket. Understand the trade-offs
+before exposing an instance to untrusted input.
+
+| Mode | `config.yaml` | Host Docker socket | Isolation |
+|------|---------------|--------------------|-----------|
+| `local` (default) | `deerflow.sandbox.local:LocalSandboxProvider` | Not mounted | Commands run **inside the gateway container** on its filesystem. Not a strong boundary — `allow_host_bash` is `false` by default and should stay off for untrusted workloads. |
+| `aio` (pure DooD) | `deerflow.community.aio_sandbox:AioSandboxProvider` (no `provisioner_url`) | **Mounted** (opt-in overlay) | Sandbox containers are started via the host Docker daemon. |
+| `provisioner` (Kubernetes) | `AioSandboxProvider` + `provisioner_url` | Not mounted | Sandbox pods are created through the provisioner's K8s API over HTTP. Strongest isolation. |
+
+#### The Docker socket is host root
+
+Mounting `/var/run/docker.sock` into a container grants that container
+**root-equivalent control of the host**: anything able to reach the socket can
+start a new container that bind-mounts the host filesystem and escape. This
+matters for DeerFlow because the gateway executes model-generated commands, so a
+prompt injection or any in-container code-execution primitive could pivot to the
+host through the socket.
+
+To keep this off the default attack surface:
+
+- The host Docker socket is **not** mounted by the default Compose stack. It is
+  added only for `aio` mode through the opt-in `docker/docker-compose.dood.yaml`
+  overlay, which `scripts/deploy.sh` and `scripts/docker.sh` append
+  automatically when `detect_sandbox_mode()` returns `aio`.
+- Prefer **provisioner/Kubernetes mode** for multi-tenant or internet-exposed
+  deployments — it isolates sandboxes without handing the gateway the host
+  daemon.
+- If you must use `aio`/DooD, treat the host as part of the gateway's trust
+  boundary: run it on a dedicated host, and consider a scoped Docker API proxy
+  instead of the raw socket.
+
+> Note: the gateway bind-mounts `$HOME/.claude` and `$HOME/.codex` (read-only)
+> for CLI auto-auth in **all** modes. These hold long-lived CLI credentials;
+> scope or omit them when the gateway runs untrusted workloads.
+
+### CLI Credential Mounts (Claude Code / Codex)
+
+DeerFlow can reuse your Claude Code / Codex CLI subscription login as a model
+provider (`ClaudeChatModel`, the Codex provider) or for ACP agents that run the
+CLI in-container. The Compose stack used to bind-mount the **entire** `~/.claude`
+and `~/.codex` directories (read-only) into the gateway container in **every**
+configuration — exposing not just credentials but full conversation history,
+per-project session data, and global CLI config. A gateway compromise (prompt
+injection, tool/MCP misuse, RCE) would leak all of it.
+
+These directories are **no longer mounted by default**. Supply CLI credentials
+with the least exposure that fits your setup:
+
+| Need | How | Exposure |
+|------|-----|----------|
+| Claude model provider | env `CLAUDE_CODE_OAUTH_TOKEN` / `ANTHROPIC_AUTH_TOKEN` (via `.env`), or `CLAUDE_CODE_CREDENTIALS_PATH` → a single mounted `.credentials.json` | none / one file |
+| Codex model provider | env `CODEX_AUTH_PATH` pointing at a single mounted `auth.json` | one file |
+| ACP agent | the adapter's own auth — many ACP adapters take an env API key (e.g. `ANTHROPIC_API_KEY` / `OPENAI_API_KEY`) and need no mount; use the opt-in `docker/docker-compose.cli-auth.yaml` overlay only if your adapter reads the full CLI config dir | none / full dir |
+
+The Gateway credential loader checks environment variables **before** the
+default credential files, so the env-token paths need no bind mount at all. ACP
+adapters authenticate independently of DeerFlow via their own documented env —
+for example the common `claude-code-acp` adapter starts as
+`ANTHROPIC_API_KEY=… claude-code-acp` and honors `CLAUDE_CONFIG_DIR` to redirect
+its config directory, so it needs no `~/.claude` mount at all. Prefer the
+adapter's documented env auth, and reach for the
+`docker-compose.cli-auth.yaml` overlay only as a fallback for an adapter that
+genuinely reads the full CLI config directory.
+
+
 ## Best Practices
 
 1. **Place `config.yaml` in project root** - Set `DEER_FLOW_PROJECT_ROOT` if the runtime starts elsewhere