docs(docker): merge-time note for the gh/az sign-in in multi-user mode (#472)

Clone Repo clears the credential helpers for a non-admin, but a non-admin's
Docker case with credential seeding on still receives a copy of the server
account's gh/az sign-in when the agent-image switches are on, the same as
the Claude and Codex credentials. Say so in the multi-user notes so the docs
do not read as a stronger guarantee than they are.

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

docker/README.md

@@ -112,7 +112,7 @@ az login --use-device-code     # then: az devops configure --defaults organizati
 
 After that, **Add Case → Clone Repo** accepts private `https://` URLs on those hosts, and `git clone` works from any session. Until a CLI is signed in its helper prints nothing, so a private clone fails immediately with the usual authentication error rather than waiting on a prompt.
 
-**Multi-user mode:** every Codeman user's git runs as the same server account, so these sign-ins would otherwise be shared. Clone Repo therefore runs a **non-admin**'s clone and preflight with every git credential helper cleared (`git -c credential.helper=`): a non-admin can clone public repositories and anything their own SSH setup allows, but not a private https repository through the admin's `gh`/`az` sign-in. Admins, and single-user mode, keep the helpers. A non-admin's own agent sessions still run as that same account; see `docs/security-architecture.md`, multi-user mode.
+**Multi-user mode:** every Codeman user's git runs as the same server account, so these sign-ins would otherwise be shared. Clone Repo therefore runs a **non-admin**'s clone and preflight with every git credential helper cleared (`git -c credential.helper=`): a non-admin can clone public repositories and anything their own SSH setup allows, but not a private https repository through the admin's `gh`/`az` sign-in. Admins, and single-user mode, keep the helpers. A non-admin's own agent sessions still run as that same account, and with the agent-image `gh`/`az` switches on, a non-admin's Docker case with credential seeding on also receives the server account's `gh`/`az` sign-in, the same as the Claude and Codex credentials; see `docs/security-architecture.md`, multi-user mode.
 
 Azure DevOps is authenticated with an Entra ID access token that the helper requests from `az` for each Git operation, so nothing is written to disk beyond `az`'s own sign-in. An account that has to use a personal access token can set `AZURE_DEVOPS_EXT_PAT` for the container instead (for example under `environment:` in `docker-compose.override.yml`); the helper prefers it when present. SSH remotes are unaffected by any of this and keep using the account's own keys.
 

docs/security-architecture.md

@@ -516,7 +516,7 @@ Full feature guide: [`docker-cases.md`](docker-cases.md).
 - **Auth is a parallel branch** (`middleware/auth.ts`) that leaves the single‑user path untouched: per‑user scrypt verify (`timingSafeEqual`, timing‑equalized against user enumeration), identity‑carrying cookies, a per‑username failure bucket (a botnet can't brute one account across IPs; one NATed user can't lock out the rest), and a `mustChangePassword` lockbox. The hook‑secret loopback bypass, host guard, and Origin/CSRF guard are unchanged (hooks authenticate the INSTANCE, not a user).
 - **Ownership is enforced server‑side only** and fails closed: `req.authUser` (a synthetic admin in single‑user), `findSessionOrFail` returns NOT_FOUND (never 403) for a foreign session, list/SSE/WS/file‑preview/search all filter by `session.owner`, and SSE routing defaults session‑scoped events to their owner (unresolved owner → withheld). The load‑bearing rule is **non‑admin `workingDir` confinement**: a non‑admin's session/one‑shot working dir must realpath‑resolve inside `~/codeman-users/<name>/cases`, checked BEFORE any disk write.
 - **Privileged actions are a one‑bit grant** (`canBypassPermissions`, default off): only granted users (and admins) get `--dangerously-skip-permissions` (others are silently downgraded to `--permission-mode auto`), shell‑mode sessions, cron `launchCommand`, and other CLIs' bypass flags. Machine‑level resources (remote/Docker host definitions, tunnel, self‑update, settings writes) are admin‑only.
-- **Clone Repo does not lend the server's git sign-in to non-admins.** A clone writes only inside the caller's own case space, so it is not admin-gated, but the server account's git credential helpers (the Docker image's opt-in `gh`/`az` helpers, or any `gh auth setup-git`) are shared by every user. A non-admin's clone and preflight therefore run with `git -c credential.helper=`, which empties the helper list including the URL-scoped entries (`cloneWithoutCredentialHelpers` in `case-routes.ts`, argv pinned in `test/git-clone.test.ts`). This closes the Clone Repo path only: the account's SSH keys still apply to an `ssh://` URL, and a non-admin's agent sessions run as the same account, consistent with the first bullet above.
+- **Clone Repo does not lend the server's git sign-in to non-admins.** A clone writes only inside the caller's own case space, so it is not admin-gated, but the server account's git credential helpers (the Docker image's opt-in `gh`/`az` helpers, or any `gh auth setup-git`) are shared by every user. A non-admin's clone and preflight therefore run with `git -c credential.helper=`, which empties the helper list including the URL-scoped entries (`cloneWithoutCredentialHelpers` in `case-routes.ts`, argv pinned in `test/git-clone.test.ts`). This closes the Clone Repo path only: the account's SSH keys still apply to an `ssh://` URL, and a non-admin's agent sessions run as the same account, consistent with the first bullet above. Docker cases are a second route to the same sign-in: with `CODEMAN_AGENT_IMAGE_INSTALL_GH`/`_AZ` on, a non-admin's Docker case with credential seeding on (the default) receives a copy of the server account's `gh`/`az` sign-in, exactly as it receives the Claude and Codex credentials.
 - **Admin actions are audited** append‑only to `~/.codeman/admin-audit.jsonl` (acting admin, action, target, IP). Passwords set by an admin create/reset are one‑time (returned once, force change). Under Basic auth, `logout` only truly ends QR‑issued sessions — to lock someone out, disable the account or reset the password (a proper login form is a deferred Phase 6).
 
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