docs(multi-user): server-wide settings writes are admin-only

api-reference gains a Settings section (GET/PUT /api/settings, the model
config, the case order and PUT /api/config, with the 403 FORBIDDEN a non-admin
gets in multi-user mode). The Multi-User Mode wiki page explains what a regular
user's App Settings save does now, Settings-Reference links it, the plan's
Settings row is marked implemented, and CLAUDE.md notes the gate for the
Multi-user paragraph and for anyone adding a settings write.

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

CLAUDE.md

@@ -239,7 +239,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 **Web tabs** (dashboard URLs as tabs): a saved URL renders as a tab beside sessions, **NOT a `SessionMode`**, and is proxied through Codeman's own origin (`/webview/<cap>/...`). ⚠️ The proxy is NOT an API surface: its capability-based auth exemption stays fenced to safe methods and non-route paths (`test/webview-auth-exemption.test.ts`). ⚠️ Iframes omit `allow-same-origin` unless `trusted`, and `Authorization`/`codeman_session` are stripped upstream in both modes. ⚠️ **Egress guard**: link-local and cloud-metadata targets are refused at save time, by a sync hostname check at each connect (IP literals skip DNS), AND on the resolved address (`webview-egress.ts`); use the `undici` package's own `fetch` + `Agent`, never Node's global fetch. ⚠️ Loopback links in agent output auto-open as proxied web tabs (`openLinkThroughWebTabIfLoopback`), but never auto-route `*.localhost` (prompt-injectable DNS). Capabilities are revoked on logout (`revokeOwner`). → [architecture-invariants#web-tabs](docs/architecture-invariants.md#web-tabs), `docs/web-tabs.md`
 
-**Multi-user mode** (opt-in `--multiuser` / `CODEMAN_MULTIUSER=1`, OFF by default): named users with scrypt-hashed passwords in `~/.codeman/users.json`. Gated everywhere by `isMultiUserMode()`; when OFF, behavior is byte-identical to single-user because every scoping helper short-circuits. ⚠️ **Not a security boundary at the agent layer**: every session still runs as the SAME OS account. This separates WORKSPACES; it does not sandbox users (Docker cases are the isolation story). Ownership threads through `Session.owner` and is enforced in `findSessionOrFail`, list endpoints, SSE routing (fail-closed), WS, search, and file-preview. → [architecture-invariants#multi-user-mode](docs/architecture-invariants.md#multi-user-mode), `docs/multi-user-plan.md`
+**Multi-user mode** (opt-in `--multiuser` / `CODEMAN_MULTIUSER=1`, OFF by default): named users with scrypt-hashed passwords in `~/.codeman/users.json`. Gated everywhere by `isMultiUserMode()`; when OFF, behavior is byte-identical to single-user because every scoping helper short-circuits. ⚠️ **Not a security boundary at the agent layer**: every session still runs as the SAME OS account. This separates WORKSPACES; it does not sandbox users (Docker cases are the isolation story). Ownership threads through `Session.owner` and is enforced in `findSessionOrFail`, list endpoints, SSE routing (fail-closed), WS, search, and file-preview. ⚠️ `settings.json` is ONE server-wide file, so every write to it is admin-only (`PUT /api/settings`, `/api/execution/model-config`, `/api/cases/order`, plus `PUT /api/config`: 403 `FORBIDDEN` before parsing), a non-admin's quick-start/Ralph start skips `lastUsedCase`, and the browser skips those writes for a non-admin via `_settingsReadOnly()` (settings-ui.js; `test/routes/system-routes-settings-admin-only.test.ts`). → [architecture-invariants#multi-user-mode](docs/architecture-invariants.md#multi-user-mode), `docs/multi-user-plan.md`
 
 **Away digest**: `GET /api/away-digest` aggregates what happened while you were away from the lifecycle log, run-summary events, live sessions, token stats, and recent subagents. Pure aggregator in `web/away-digest.ts`. ⚠️ Returns `{success:true,digest}`, a legacy raw-ish shape consistent with the other raw GET handlers in `system-routes.ts`; frontend and tests read `.digest`. → [architecture-invariants#away-digest](docs/architecture-invariants.md#away-digest)
 
@@ -293,7 +293,7 @@ One module per domain in `src/web/routes/` (plus a barrel; `ls src/web/routes/`
 - **API endpoint**: Types in `src/types/` domain file, route in `src/web/routes/*-routes.ts`. Return the `ApiResponse` envelope (`{ success: true, data }`; errors via `createErrorResponse()` with proper status code). Validate with Zod schemas in `schemas.ts`.
 - **SSE event**: Add to `src/web/sse-events.ts` + `SSE_EVENTS` in `constants.js`, emit via `broadcast()`, handle in `app.js` (`addListener(`)
 - **Session setting**: Add to `SessionState`, include in `session.toState()`, call `persistSessionState()`
-- **App setting**: decide per-device vs synced first. Per-device keys go in the `displayKeys` set in settings-ui.js and must NOT be added to `SettingsUpdateSchema` (it is `.strict()`). ⚠️ Anything in `PUT /api/settings` that acts on a setting (the `toggleService` watcher calls) must resolve from **`merged`** (persisted + incoming), never from the raw request body: a partial PUT omits keys it doesn't intend to change, and `body.x ?? default` turns every omission into "apply the default" and silently resets live services. Pinned by `test/routes/system-routes-settings-partial-put.test.ts`.
+- **App setting**: decide per-device vs synced first. Per-device keys go in the `displayKeys` set in settings-ui.js and must NOT be added to `SettingsUpdateSchema` (it is `.strict()`). ⚠️ Anything in `PUT /api/settings` that acts on a setting (the `toggleService` watcher calls) must resolve from **`merged`** (persisted + incoming), never from the raw request body: a partial PUT omits keys it doesn't intend to change, and `body.x ?? default` turns every omission into "apply the default" and silently resets live services. Pinned by `test/routes/system-routes-settings-partial-put.test.ts`. ⚠️ A synced setting is admin-only to write in multi-user mode (the PUT 403s a non-admin, whose browser does not send it): a new route that writes `settings.json` takes the same `isMultiUserMode() && !requireAdmin(req, reply)` gate.
 - **Hook event**: Add to `HookEventType`, add hook in `hooks-config.ts:generateHooksConfig()`, update `HookEventSchema`
 - **Mobile feature**: Add to relevant singleton, guard with `MobileDetection.isMobile()`. New header buttons must stay off phones (`test/mobile-header-buttons-policy.test.ts`).
 - **New test**: a test that constructs `WebServer` itself binds port 0 (`new WebServer(0, …)`, then `server.boundPort`), and a raw `http`/`net`/Fastify/`ws` server listens on `0` and reads `address().port`; mobile tests get theirs from `createTestServer()` and read `boundPort` too. `test/test-ports-guard.test.ts` refuses a fixed port in either. Route tests use `app.inject()` (no port needed); see `test/routes/_route-test-utils.ts`.

docs/api-reference.md

@@ -1079,6 +1079,21 @@ A local case whose folder is the top of a git repository can keep **worktrees**
 
 **Starting a session in a worktree** goes through the normal create paths: `POST /api/quick-start` takes `worktree: "<name>"` next to `caseName` and runs the session (and the hooks, the agent skill and `modelOverride`) in the worktree folder; the response adds `worktree` and `workingDir`. It is refused for remote and Docker cases (`400`), for a worktree that is not a registered, managed one (`404`), and for a case that does not exist (`404`: a worktree launch never scaffolds a case). `POST /api/sessions` takes the worktree path as `workingDir` like any other folder.
 
+## Settings
+
+`~/.codeman/settings.json` is one file for the whole server: the synced App Settings (feature switches, the plan-usage collection switch `showPlanUsageLimits`, `runMode`, `respawnPresets`, `tunnelEnabled`, ...), plus `modelConfig`, `caseOrder` and `lastUsedCase`. Reads are open to every signed-in user. **In multi-user mode every write is admin only:** for a non-admin the routes below answer `403 FORBIDDEN` before the body is even validated, so nothing is written, no watcher is toggled and no tunnel is started. Single-user mode is unaffected.
+
+| Method | Path                          | Body                                 | Notes |
+| ------ | ----------------------------- | ------------------------------------ | ----- |
+| `GET`  | `/api/settings`               | none                                 | The stored settings object. Never writes. |
+| `PUT`  | `/api/settings`               | partial settings (strict schema)     | Merged into the stored file; services (watchers, tunnel, tmux history limit) reconcile to the merged result. `403 FORBIDDEN` for a non-admin in multi-user mode. A tunnel enable without `CODEMAN_PASSWORD` is refused separately (`403 OPERATION_FAILED`, resend with `acknowledgeUnauthTunnel: true`). |
+| `GET`  | `/api/execution/model-config` | none                                 | `modelConfig` (cron's and the plan orchestrator's default model). |
+| `PUT`  | `/api/execution/model-config` | `{ defaultModel?, agentTypeOverrides?, ... }` | Replaces `modelConfig`. `403 FORBIDDEN` for a non-admin in multi-user mode. |
+| `PUT`  | `/api/cases/order`            | `{ order: string[] }`                | The one case order every user's `GET /api/cases` is sorted by. `403 FORBIDDEN` for a non-admin in multi-user mode. |
+| `PUT`  | `/api/config`                 | `{ pollIntervalMs?, defaultTimeoutMs?, maxConcurrentSessions?, respawn? }` (strict) | The process-wide app config in `state.json`. `403 FORBIDDEN` for a non-admin in multi-user mode. |
+
+A non-admin's `POST /api/quick-start` and `POST /api/ralph-loop/start` work as before but do not record their case as `lastUsedCase` (every user can read it).
+
 ## CLI management
 
 Read and write the CLI registry (`docs/cli-registry.md`). Every **write** route answers `403 FORBIDDEN` while `cliManagementEnabled` is off (the default), and for a non-admin in multi-user mode. A write that would overwrite a `clis.json` which does not parse, or which has group/world permission bits, is refused with `409 CONFLICT` and a message naming the fix; the file is left untouched.

docs/multi-user-plan.md

@@ -161,7 +161,7 @@ Codeman now ships a global **Startup Mode** picker (App Settings, Claude CLI tab
 | Screenshots `/api/screenshots` (deprecated)                                | Deprecated: removed in a later MAJOR, so no per-user subdir is planned; the replacement `POST /api/sessions/:id/paste-image` is already session-scoped. Former plan: per-user subdir `~/.codeman/screenshots/<username>/` in multi-user mode. Note: `GET /:name` deliberately rejects `/` in names as traversal, so derive the subdir server-side from `req.authUser` and keep client-visible names flat                                                  |
 | Attachments                                                                | Already session-scoped; inherits the session owner check. `attachmentConfineToWorkspace` is a global, default-OFF setting today: in multi-user mode it is FORCED ON for non-admins regardless of the setting (their attachments must resolve inside their own space); the setting keeps meaning what it means for admins                                                                                                                                  |
 | File routes (browse/preview)                                               | Path allowlist adds: non-admin paths must resolve (realpath) inside their own space or their own sessions' workingDirs                                                                                                                                                                                                                                                                                                                                    |
-| Settings (`settings.json`)                                                 | Global, admin-only writes in multi-user mode; reads allowed (per-device display keys stay in localStorage as today). Per-user server settings: out of scope v1                                                                                                                                                                                                                                                                                            |
+| Settings (`settings.json`)                                                 | Global, admin-only writes in multi-user mode; reads allowed (per-device display keys stay in localStorage as today). **Implemented (1.42.0):** `PUT /api/settings`, `PUT /api/execution/model-config`, `PUT /api/config` and `PUT /api/cases/order` answer 403 `FORBIDDEN` to a non-admin before parsing anything; quick-start and Ralph loop start skip a non-admin's `lastUsedCase`; the browser skips those writes for a non-admin (`_settingsReadOnly()`, settings-ui.js). Per-user server settings: out of scope v1|
 | System ops (self-update, tunnel toggle, span-displays, docker image build) | Admin-only                                                                                                                                                                                                                                                                                                                                                                                                                                                |
 | `getLightState` init snapshot                                              | Filtered per connection. Actual contents to filter (verified): `sessions`, `scheduledRuns`, `respawnStatus`, `subagents`, `workflowRuns`, `planUsage` (host-plan telemetry: admin-only); `globalStats` stays coarse-global. Cron jobs are NOT in the snapshot (they have their own REST route; filter there). The snapshot is cached process-wide (`LIGHT_STATE_CACHE_TTL_MS`): either key the cache per role/user or filter AFTER the cache on each send |
 

docs/wiki/Multi-User-Mode.md

@@ -60,6 +60,27 @@ Admins see everything.
 Ownership threads through every list endpoint, the session lookup helper, the WebSocket
 layer, and file previews. A user cannot address another user's session even by id.
 
+## Server-wide settings are admin only
+
+There is one set of server settings (`~/.codeman/settings.json`) for everyone: the feature
+switches, the run mode, respawn presets, the case order, the Cloudflare tunnel, the default
+models. Every user can **read** them, but only an **admin** can change them. For a regular
+user the settings write routes answer `403 FORBIDDEN` (see the
+[HTTP API](HTTP-API) and [`docs/api-reference.md`](https://github.com/Ark0N/Codeman/blob/master/docs/api-reference.md)).
+
+In the browser this means:
+
+- **App Settings → Save** still keeps a regular user's per-device settings (skin, fonts,
+  header buttons, keyboard bar and the rest of the per-device keys) on that device. If they
+  also changed a server-wide setting, one notice says it can only be changed by an admin,
+  and the setting keeps the server's value.
+- A regular user's run-mode pick and respawn presets are kept in that browser and not sent
+  to the server, and their last used case is not recorded server-wide. What an admin set
+  still loads on the next visit.
+- Reordering cases and switching the tunnel on or off are admin actions.
+
+Per-user server settings are not part of this version.
+
 ## Safer defaults for regular users
 
 Non-admins get tighter defaults, and lifting them is an explicit per-user grant:

docs/wiki/Settings-Reference.md

@@ -29,6 +29,10 @@ The practical rule: **appearance and input are per device, behaviour is shared.*
 did not follow you, it is in one of the first two rows, and you change it again on that
 device.
 
+In [Multi-User Mode](Multi-User-Mode) the server's settings are shared by every user, so
+only an **admin** can change them. A regular user's **Save** keeps their per-device settings
+as usual and tells them that server-wide settings can only be changed by an admin.
+
 ## App Settings
 
 ### Updates