feat(frontend): panneau Settings Deployment et gateway serveur desktop (#68 F1+F2)

Donne à l'utilisateur la surface pour activer le serveur depuis l'app.

- `features/settings/` : `SettingsView`, `DeploymentSettings`, `useDeployment`.
- `adapters/desktopServer.ts` + port `DesktopServerGateway` et DTO associés ;
  adapters mock et http/unsupported alignés (le mode web n'expose pas le
  contrôle du serveur qui l'héberge).
- `ProjectsView` : le `showSettings: boolean` devient une navigation interne
  `AI Profiles` / `Deployment`. Le libellé alternant « Close AI Profiles »
  disparaît — Settings existait déjà dans cette vue, la surface évolue au lieu
  d'ajouter un `PanelId`.

CORRECTION D'UN BRIEF FAUX, remontée spontanément par DevFrontend et qui mérite
de survivre : le cadrage décrivait le mode `remoteProxyOtherMachine` avec deux
champs. `validate_settings` en exige un troisième, `lanBindAddress`, et rejette
loopback comme unspecified. Construit selon la spec, chaque save et chaque start
en mode 3 aurait échoué — le lot serait parti vert et cassé. Le panneau expose
donc un select alimenté par `candidateLanAddresses` fourni par le backend :
la règle « le frontend n'invente jamais une IP » tient.

QA ré-exécutée par Git avant merge : `npm run typecheck` exit 0 ·
`npx vitest run` 87 files / 789 passed, 0 échec.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/adapters/desktopServer.ts

@@ -0,0 +1,82 @@
+/**
+ * Tauri adapter for {@link DesktopServerGateway} (ticket #68). One of the only
+ * places that calls `invoke()`; features reach it exclusively through the port.
+ *
+ * Commands and payload keys are camelCase, matching the backend DTO convention.
+ * `save_server_exposure_settings` / `preview_server_exposure_settings` take the
+ * settings directly under a `settings` key (no `request` wrapper).
+ *
+ * **Polling note.** The backend exposes no status *event* — `embedded_server.rs`
+ * emits nothing — so `onStatusChanged` is implemented here by polling
+ * `embedded_server_status`. That keeps the port shape push-like (and swappable
+ * for a real event later) while the polling schedule stays an adapter detail.
+ */
+
+import { invoke } from "@tauri-apps/api/core";
+
+import type {
+  EmbeddedServerStatus,
+  ServerExposurePreview,
+  ServerExposureSettings,
+  Unsubscribe,
+} from "@/domain";
+import type { DesktopServerGateway } from "@/ports";
+
+/** Status poll interval (ms). Cheap, in-process command; transitions are coarse. */
+const STATUS_POLL_MS = 2000;
+
+export class TauriDesktopServerGateway implements DesktopServerGateway {
+  constructor(private readonly pollMs: number = STATUS_POLL_MS) {}
+
+  getExposureSettings(): Promise<ServerExposureSettings> {
+    return invoke<ServerExposureSettings>("get_server_exposure_settings");
+  }
+
+  async saveExposureSettings(settings: ServerExposureSettings): Promise<void> {
+    await invoke("save_server_exposure_settings", { settings });
+  }
+
+  previewExposure(
+    settings: ServerExposureSettings,
+  ): Promise<ServerExposurePreview> {
+    return invoke<ServerExposurePreview>("preview_server_exposure_settings", {
+      settings,
+    });
+  }
+
+  status(): Promise<EmbeddedServerStatus> {
+    return invoke<EmbeddedServerStatus>("embedded_server_status");
+  }
+
+  start(): Promise<EmbeddedServerStatus> {
+    return invoke<EmbeddedServerStatus>("embedded_server_start");
+  }
+
+  stop(): Promise<EmbeddedServerStatus> {
+    return invoke<EmbeddedServerStatus>("embedded_server_stop");
+  }
+
+  async onStatusChanged(
+    handler: (status: EmbeddedServerStatus) => void,
+  ): Promise<Unsubscribe> {
+    let stopped = false;
+    const timer = setInterval(() => {
+      void this.status().then(
+        (status) => {
+          // The unsubscribe may land while a poll is in flight; drop late results
+          // so a torn-down consumer never gets called.
+          if (!stopped) handler(status);
+        },
+        () => {
+          // A failed poll is not a status: swallow it and let the next tick try
+          // again, rather than tearing the subscription down.
+        },
+      );
+    }, this.pollMs);
+
+    return () => {
+      stopped = true;
+      clearInterval(timer);
+    };
+  }
+}

frontend/src/adapters/http/index.ts

@@ -42,6 +42,7 @@ import {
   HttpTicketGateway,
 } from "./streamGateways";
 import {
+  WebDesktopServerGateway,
   WebFocusedProjectGateway,
   WebRemoteGateway,
   WebWindowGateway,
@@ -121,6 +122,9 @@ export function createHttpWsGateways(config: HttpWsGatewaysConfig = {}): Gateway
     remote: new WebRemoteGateway(),
     profile: new HttpProfileGateway(http),
     modelServer: new HttpModelServerGateway(http),
+    // Desktop-only (#68): the web client is served *by* the embedded server and
+    // must not reconfigure it.
+    desktopServer: new WebDesktopServerGateway(),
     template: new HttpTemplateGateway(http),
     skill: new HttpSkillGateway(http),
     memory: new HttpMemoryGateway(http),

frontend/src/adapters/http/unsupported.ts

@@ -9,8 +9,15 @@
  * browser to replace `pickFolder`), it gets its own lot.
  */
 
-import type { GatewayError, Unsubscribe } from "@/domain";
 import type {
+  EmbeddedServerStatus,
+  GatewayError,
+  ServerExposurePreview,
+  ServerExposureSettings,
+  Unsubscribe,
+} from "@/domain";
+import type {
+  DesktopServerGateway,
   FocusedProject,
   FocusedProjectGateway,
   RemoteGateway,
@@ -75,3 +82,40 @@ export class WebRemoteGateway implements RemoteGateway {
     return unsupportedOnWeb("Remote (SSH/WSL) connection");
   }
 }
+
+/**
+ * Web stub: the embedded server is desktop-only (ticket #68). A web client is
+ * *served by* this very server, so letting it reconfigure or stop the server
+ * would let a remote device saw off the branch it sits on. The desktop app owns
+ * this surface; every call fails explicitly rather than reaching for Tauri.
+ */
+export class WebDesktopServerGateway implements DesktopServerGateway {
+  // `async` on purpose: these must *reject* rather than throw synchronously, so
+  // callers using `.then(ok, err)` (not just `await`) still see the failure.
+  async getExposureSettings(): Promise<ServerExposureSettings> {
+    return unsupportedOnWeb("Embedded server settings");
+  }
+  async saveExposureSettings(_settings: ServerExposureSettings): Promise<void> {
+    return unsupportedOnWeb("Embedded server settings");
+  }
+  async previewExposure(
+    _settings: ServerExposureSettings,
+  ): Promise<ServerExposurePreview> {
+    return unsupportedOnWeb("Embedded server settings");
+  }
+  async status(): Promise<EmbeddedServerStatus> {
+    return unsupportedOnWeb("Embedded server status");
+  }
+  async start(): Promise<EmbeddedServerStatus> {
+    return unsupportedOnWeb("Starting the embedded server");
+  }
+  async stop(): Promise<EmbeddedServerStatus> {
+    return unsupportedOnWeb("Stopping the embedded server");
+  }
+  onStatusChanged(
+    _handler: (status: EmbeddedServerStatus) => void,
+  ): Promise<Unsubscribe> {
+    // Never fires on web; a no-op unsubscribe keeps callers' teardown honest.
+    return Promise.resolve(() => {});
+  }
+}

frontend/src/adapters/index.ts

@@ -20,6 +20,7 @@ import { TauriTerminalGateway } from "./terminal";
 import { TauriLayoutGateway } from "./layout";
 import { TauriProfileGateway } from "./profile";
 import { TauriModelServerGateway } from "./modelServer";
+import { TauriDesktopServerGateway } from "./desktopServer";
 import { TauriTemplateGateway } from "./template";
 import { TauriSkillGateway } from "./skill";
 import { TauriMemoryGateway } from "./memory";
@@ -60,6 +61,7 @@ export function createTauriGateways(): Gateways {
     remote: new TauriRemoteGateway(),
     profile: new TauriProfileGateway(),
     modelServer: new TauriModelServerGateway(),
+    desktopServer: new TauriDesktopServerGateway(),
     template: new TauriTemplateGateway(),
     skill: new TauriSkillGateway(),
     memory: new TauriMemoryGateway(),
@@ -83,6 +85,7 @@ export {
   TauriLayoutGateway,
   TauriProfileGateway,
   TauriModelServerGateway,
+  TauriDesktopServerGateway,
   TauriTemplateGateway,
   TauriSkillGateway,
   TauriMemoryGateway,

frontend/src/adapters/mock/index.ts

@@ -8,9 +8,11 @@ import type {
   Agent,
   AgentDrift,
   AgentProfile,
+  DiagnosticWarning,
   DomainEvent,
   EmbedderEngines,
   EmbedderProfile,
+  EmbeddedServerStatus,
   FirstRunState,
   GatewayError,
   GitBranches,
@@ -36,6 +38,8 @@ import type {
   ProjectWorkState,
   ProfileAvailability,
   ResumableAgent,
+  ServerExposurePreview,
+  ServerExposureSettings,
   Skill,
   ReplyChunk,
   SkillScope,
@@ -63,6 +67,7 @@ import type {
   CreateAgentInput,
   CreateMemoryInput,
   CreateSkillInput,
+  DesktopServerGateway,
   EmbedderGateway,
   CreateTemplateInput,
   Gateways,
@@ -1373,6 +1378,148 @@ export class MockModelServerGateway implements ModelServerGateway {
   }
 }
 
+/** Mirror of the backend `default_settings()` (ticket #68). */
+const DEFAULT_EXPOSURE_SETTINGS: ServerExposureSettings = {
+  mode: "localOnly",
+  port: 17373,
+  trustedProxies: [],
+};
+
+/** Fixed LAN candidates so the offline UI has something to pick from. */
+const MOCK_LAN_ADDRESSES = ["192.168.1.42", "10.0.0.17"];
+
+function invalid(message: string): never {
+  const err: GatewayError = { code: "INVALID", message };
+  throw err;
+}
+
+/**
+ * In-memory embedded-server gateway (ticket #68).
+ *
+ * Mirrors the backend `validate_settings` / `preview_settings` closely enough
+ * that the Deployment UI — including its rejection paths — is testable offline.
+ * It is never the source of truth: production runs the real Tauri commands.
+ * `candidateLanAddresses` is fixed data here precisely because the UI must take
+ * addresses from the gateway rather than deriving them.
+ */
+export class MockDesktopServerGateway implements DesktopServerGateway {
+  private settings: ServerExposureSettings = structuredClone(
+    DEFAULT_EXPOSURE_SETTINGS,
+  );
+  private current: EmbeddedServerStatus = { state: "stopped" };
+  private readonly handlers = new Set<(s: EmbeddedServerStatus) => void>();
+
+  async getExposureSettings(): Promise<ServerExposureSettings> {
+    return structuredClone(this.settings);
+  }
+
+  async saveExposureSettings(settings: ServerExposureSettings): Promise<void> {
+    this.validate(settings);
+    this.settings = structuredClone(settings);
+  }
+
+  async previewExposure(
+    settings: ServerExposureSettings,
+  ): Promise<ServerExposurePreview> {
+    // The real `preview_server_exposure_settings` validates *before* previewing,
+    // so an incomplete draft is rejected rather than previewed. Mirrored here —
+    // the UI relies on it as its validation authority.
+    this.validate(settings);
+    const warnings: DiagnosticWarning[] = [];
+    if (
+      settings.mode === "remoteProxyOtherMachine" &&
+      settings.trustedProxies.length === 0
+    ) {
+      // Mirrors the backend's `missingTrustedProxy` warning — which the backend
+      // itself cannot currently reach, since `validate_settings` rejects an
+      // empty `trustedProxies` for this mode first. Kept aligned on purpose: if
+      // the backend reorders, the mock already matches.
+      warnings.push({
+        code: "missingTrustedProxy",
+        message:
+          "Add the IP address or CIDR of the reverse proxy that connects to this server.",
+      });
+    }
+    const bindAddress =
+      settings.mode === "remoteProxyOtherMachine"
+        ? settings.lanBindAddress
+        : "127.0.0.1";
+    const upstreamUrl =
+      settings.mode !== "localOnly" && bindAddress
+        ? `http://${bindAddress}:${settings.port}`
+        : undefined;
+    return {
+      candidateLanAddresses: [...MOCK_LAN_ADDRESSES],
+      upstreamUrl,
+      warnings,
+    };
+  }
+
+  async status(): Promise<EmbeddedServerStatus> {
+    return structuredClone(this.current);
+  }
+
+  async start(): Promise<EmbeddedServerStatus> {
+    // The backend re-validates on start; a bad config fails there, not silently.
+    this.validate(this.settings);
+    const preview = await this.previewExposure(this.settings);
+    this.emit({
+      state: "running",
+      localUrl: `http://127.0.0.1:${this.settings.port}`,
+      publicUrl:
+        this.settings.mode === "localOnly"
+          ? undefined
+          : this.settings.publicOrigin,
+      upstreamUrl: preview.upstreamUrl,
+      // Runtime-only, regenerated per start — never persisted.
+      pairingCode: "MOCK-PAIR-4242",
+    });
+    return structuredClone(this.current);
+  }
+
+  async stop(): Promise<EmbeddedServerStatus> {
+    this.emit({ state: "stopped" });
+    return structuredClone(this.current);
+  }
+
+  async onStatusChanged(
+    handler: (status: EmbeddedServerStatus) => void,
+  ): Promise<Unsubscribe> {
+    this.handlers.add(handler);
+    return () => this.handlers.delete(handler);
+  }
+
+  /** Test hook: force a status (e.g. a `failed` state) and notify subscribers. */
+  setStatus(status: EmbeddedServerStatus): void {
+    this.emit(status);
+  }
+
+  private emit(status: EmbeddedServerStatus): void {
+    this.current = status;
+    for (const handler of this.handlers) handler(structuredClone(status));
+  }
+
+  private validate(settings: ServerExposureSettings): void {
+    if (settings.mode !== "localOnly") {
+      const origin = settings.publicOrigin;
+      if (!origin) invalid("remote exposure requires publicOrigin");
+      if (!origin.startsWith("https://")) {
+        invalid("remote exposure requires publicOrigin to start with https://");
+      }
+      if (origin.includes("*")) invalid("publicOrigin must be exact, not a wildcard");
+      if (origin.endsWith("/")) invalid("publicOrigin must not end with '/'");
+    }
+    if (settings.mode === "remoteProxyOtherMachine") {
+      if (!settings.lanBindAddress) {
+        invalid("remoteProxyOtherMachine requires lanBindAddress");
+      }
+      if (settings.trustedProxies.length === 0) {
+        invalid("remoteProxyOtherMachine requires at least one trustedProxies entry");
+      }
+    }
+  }
+}
+
 /**
  * Stateful in-memory template gateway.
  *
@@ -2630,6 +2777,7 @@ export function createMockGateways(): Gateways {
     remote: new MockRemoteGateway(),
     profile: new MockProfileGateway(),
     modelServer: new MockModelServerGateway(),
+    desktopServer: new MockDesktopServerGateway(),
     template: new MockTemplateGateway(agentGateway),
     skill: new MockSkillGateway(agentGateway),
     memory: new MockMemoryGateway(),

frontend/src/adapters/mock/mock.test.ts

@@ -16,6 +16,7 @@ describe("createMockGateways", () => {
     expect(Object.keys(gateways).sort()).toEqual([
       "agent",
       "conversation",
+      "desktopServer",
       "embedder",
       "focusedProject",
       "git",

frontend/src/domain/index.ts

@@ -117,6 +117,97 @@ export interface ModelServerCommandPreview {
   display: string;
 }
 
+/**
+ * How the embedded web server is exposed (ticket #68, mirror of the backend
+ * `ServerExposureMode`).
+ *
+ * - `localOnly` — binds loopback, no remote access.
+ * - `remoteProxyLocal` — binds loopback; an HTTPS reverse proxy runs on *this*
+ *   machine and reaches IdeA over loopback.
+ * - `remoteProxyOtherMachine` — binds a concrete LAN address so a proxy on
+ *   *another* host can reach it; that proxy must be declared in
+ *   `trustedProxies`.
+ */
+export type ServerExposureMode =
+  | "localOnly"
+  | "remoteProxyLocal"
+  | "remoteProxyOtherMachine";
+
+/**
+ * Persisted embedded-server exposure settings (mirror of the backend
+ * `ServerExposureSettingsDto`).
+ *
+ * The backend validates every field on save/start; the UI never derives network
+ * facts (LAN addresses, upstream URL) from these — it asks `previewExposure`.
+ */
+export interface ServerExposureSettings {
+  mode: ServerExposureMode;
+  /** TCP port to bind. `0` asks the OS for an ephemeral port. */
+  port: number;
+  /** Public HTTPS origin, required by both remote modes. */
+  publicOrigin?: string;
+  /**
+   * Peers allowed to contact IdeA, as IPs or CIDRs. **Not** a listen address.
+   * Required (non-empty) by `remoteProxyOtherMachine`.
+   */
+  trustedProxies: string[];
+  /**
+   * Concrete LAN address to bind, required by `remoteProxyOtherMachine`. Must
+   * come from {@link ServerExposurePreview.candidateLanAddresses} — the UI is
+   * never allowed to invent one.
+   */
+  lanBindAddress?: string;
+}
+
+/** A non-fatal diagnostic from the exposure preview (never blocks a start). */
+export interface DiagnosticWarning {
+  /** Stable warning code (e.g. `missingTrustedProxy`). */
+  code: string;
+  /** Human-readable, actionable message. */
+  message: string;
+}
+
+/**
+ * Backend-derived preview of a draft exposure config (mirror of
+ * `ServerExposurePreviewDto`). The backend is the sole authority on LAN
+ * addresses and the proxy upstream URL.
+ */
+export interface ServerExposurePreview {
+  /** LAN addresses the backend discovered on this host. */
+  candidateLanAddresses: string[];
+  /** URL the reverse proxy should target; absent in `localOnly`. */
+  upstreamUrl?: string;
+  /** Non-fatal diagnostics to surface alongside the form. */
+  warnings: DiagnosticWarning[];
+}
+
+/** Embedded-server lifecycle state (mirror of `EmbeddedServerStatusStateDto`). */
+export type EmbeddedServerState =
+  | "stopped"
+  | "starting"
+  | "running"
+  | "stopping"
+  | "failed";
+
+/**
+ * Embedded-server status (mirror of `EmbeddedServerStatusDto`). `pairingCode`
+ * is a runtime-only secret: it exists while the server runs, is never
+ * persisted, and must never be written into a settings field.
+ */
+export interface EmbeddedServerStatus {
+  state: EmbeddedServerState;
+  /** Local URL, when running. */
+  localUrl?: string;
+  /** Public URL, when a remote mode is configured. */
+  publicUrl?: string;
+  /** Upstream URL to hand to the reverse proxy. */
+  upstreamUrl?: string;
+  /** Runtime pairing code — present only while running. */
+  pairingCode?: string;
+  /** Last failure, when `state` is `failed`. */
+  error?: GatewayError;
+}
+
 /** A domain event relayed from the backend (tagged union on `type`). */
 export type DomainEvent =
   | { type: "projectCreated"; projectId: string }

frontend/src/features/projects/ProjectsView.tsx

@@ -9,9 +9,13 @@
  *   │ MENU BAR   Panneaux │ Settings                        │
  *   ├───────────────────────────────────────────────────────┤
  *   │  MAIN — LayoutGrid (fills the FULL width)             │
- *   │  — or the projects manager / welcome when no project  │
+ *   │  — or Settings / the projects manager / welcome       │
  *   └───────────────────────────────────────────────────────┘
  *
+ * **Settings** (`Settings → AI Profiles | Deployment`, #68) is a main surface
+ * with its own internal section nav — it has no `PanelId` and is outside the
+ * `viewPlacement` model, unlike every panel below.
+ *
  * The former left sidebar is gone: every panel (context, work, tickets, agents,
  * templates, skills, permissions, memory, git, projects) is reached from the
  * single **Panneaux** menu (#26), whose per-panel submenu picks the placement
@@ -34,7 +38,12 @@ import { useEffect, useState, type ReactNode } from "react";
 import type { DomainEvent, LayoutInfo } from "@/domain";
 import { LayoutGrid, LayoutTabs } from "@/features/layout";
 import { ConversationViewer } from "@/features/conversations";
-import { ProfilesSettings } from "@/features/first-run";
+import {
+  SettingsView,
+  SETTINGS_SECTIONS,
+  SETTINGS_SECTION_LABEL,
+  type SettingsSection,
+} from "@/features/settings";
 import { GitGraphView } from "@/features/git";
 import {
   Button,
@@ -114,10 +123,13 @@ export function ProjectsView() {
   // Width (px) of each dock column, driven by the DockRegion resize handle.
   const [leftDockWidth, setLeftDockWidth] = useState(340);
   const [rightDockWidth, setRightDockWidth] = useState(340);
-  // Top-level view switch (#16): when true, the main area shows the AI Profiles
-  // settings instead of the project surface. The single menu bar stays visible
-  // so the user can toggle back from Settings → AI Profiles.
-  const [showSettings, setShowSettings] = useState(false);
+  // Top-level view switch (#16, extended in #68): the open Settings section, or
+  // null when the main area shows the project surface. Settings is a main
+  // surface with its own internal nav — deliberately not a placeable panel. The
+  // menu bar stays visible above it.
+  const [settingsSection, setSettingsSection] = useState<SettingsSection | null>(
+    null,
+  );
   // The active layout (id + kind), reported by LayoutTabs — the single source of
   // truth. `kind` decides whether the main area is the terminal grid or the git
   // graph view.
@@ -390,17 +402,17 @@ export function ProjectsView() {
     {
       id: "settings",
       label: "Settings",
-      items: [
-        {
-          id: "ai-profiles",
-          label: showSettings ? "Close AI Profiles" : "AI Profiles",
-          active: showSettings,
-          onSelect: () => {
-            setShowSettings((v) => !v);
-            dismissFloating();
-          },
+      // One entry per section (#68). The entries name sections and mark the open
+      // one; closing lives in the view ("Close Settings"), so no label alternates.
+      items: SETTINGS_SECTIONS.map((section) => ({
+        id: section,
+        label: SETTINGS_SECTION_LABEL[section],
+        active: settingsSection === section,
+        onSelect: () => {
+          setSettingsSection(section);
+          dismissFloating();
         },
-      ],
+      })),
     },
   ];
 
@@ -621,7 +633,7 @@ export function ProjectsView() {
         onClose={(id) => void vm.closeTab(id)}
         projectsPanelOpen={placementOf(placements, "projects") !== "closed"}
         onOpenProjectsPanel={() => {
-          setShowSettings(false);
+          setSettingsSection(null);
           setPlacement("projects", "floating");
         }}
       />
@@ -645,14 +657,14 @@ export function ProjectsView() {
 
         {/* ── Main: AI Profiles / terminal grid / git graph / welcome ── */}
         <main className="flex min-w-0 flex-1 flex-col overflow-hidden">
-        {showSettings ? (
-          // Top-level view switch (#16): AI Profiles settings takes over the main
-          // area while the menu bar above stays visible to toggle back.
-          <div className="flex flex-1 justify-center overflow-y-auto p-6">
-            <div className="w-full max-w-2xl">
-              <ProfilesSettings />
-            </div>
-          </div>
+        {settingsSection ? (
+          // Top-level view switch (#16/#68): Settings takes over the main area
+          // while the menu bar above stays visible.
+          <SettingsView
+            section={settingsSection}
+            onSectionChange={setSettingsSection}
+            onClose={() => setSettingsSection(null)}
+          />
         ) : active && viewerConversationId ? (
           <ConversationViewer
             key={`${active.id}-${viewerConversationId}`}
@@ -740,7 +752,7 @@ export function ProjectsView() {
                   (tab) => tab.id === toast.projectId,
                 );
                 if (projectOpen) vm.activateTab(toast.projectId);
-                setShowSettings(false);
+                setSettingsSection(null);
                 setViewerConversationId(null);
                 setPlacement("work", "floating");
                 setTaskToasts((prev) =>

frontend/src/features/projects/projects.test.tsx

@@ -12,7 +12,7 @@ import {
   fireEvent,
 } from "@testing-library/react";
 
-import { MockAgentGateway, MockGitGateway, MockProfileGateway, MockProjectGateway, MockSystemGateway, MockTemplateGateway, MockWindowGateway, MockWorkStateGateway } from "@/adapters/mock";
+import { MockAgentGateway, MockDesktopServerGateway, MockGitGateway, MockProfileGateway, MockProjectGateway, MockSystemGateway, MockTemplateGateway, MockWindowGateway, MockWorkStateGateway } from "@/adapters/mock";
 import type { Gateways } from "@/ports";
 import { DIProvider } from "@/app/di";
 import { ProjectsView } from "./ProjectsView";
@@ -25,6 +25,7 @@ function renderView(
   // The project gateway drives the primary assertions; agent + profile stubs are
   // required because ProjectsView now renders AgentsPanel for the active tab.
   // template gateway is required because ProjectsView now renders TemplatesPanel.
+  // desktopServer is required by Settings → Deployment (#68).
   const agentGateway = new MockAgentGateway();
   const gateways = {
     system,
@@ -35,6 +36,7 @@ function renderView(
     git: new MockGitGateway(),
     workState: new MockWorkStateGateway(),
     window: new MockWindowGateway(),
+    desktopServer: new MockDesktopServerGateway(),
   } as unknown as Gateways;
   return {
     project,
@@ -197,7 +199,7 @@ describe("ProjectsView (with MockProjectGateway)", () => {
     expect(betaTab.getAttribute("aria-selected")).toBe("true");
   });
 
-  it("toggles the AI Profiles view from the single Settings menu (#16)", async () => {
+  it("opens the Settings surface from the Settings menu and closes it from the view (#16/#68)", async () => {
     renderView();
     await waitForIdle();
 
@@ -210,14 +212,31 @@ describe("ProjectsView (with MockProjectGateway)", () => {
     expect(await screen.findByLabelText("ai profiles settings")).toBeTruthy();
     expect(screen.queryByLabelText("project name")).toBeNull();
 
-    // Settings → Close AI Profiles returns to the project surface.
-    openMenuItem("Settings", "Close AI Profiles");
+    // #68: closing is an explicit action in the view, not an alternating menu
+    // label — the label never scaled past one section.
+    fireEvent.click(screen.getByRole("button", { name: "Close Settings" }));
     await waitFor(() =>
       expect(screen.getByLabelText("project name")).toBeTruthy(),
     );
     expect(screen.queryByLabelText("ai profiles settings")).toBeNull();
   });
 
+  it("navigates between Settings sections from the menu and the nav column (#68)", async () => {
+    renderView();
+    await waitForIdle();
+
+    // The Settings menu now names sections; Deployment opens directly.
+    openMenuItem("Settings", "Deployment");
+    expect(await screen.findByLabelText("deployment settings")).toBeTruthy();
+    expect(screen.queryByLabelText("ai profiles settings")).toBeNull();
+
+    // The internal nav column switches sections without leaving Settings.
+    const nav = screen.getByRole("navigation", { name: "settings sections" });
+    fireEvent.click(within(nav).getByRole("button", { name: "AI Profiles" }));
+    expect(await screen.findByLabelText("ai profiles settings")).toBeTruthy();
+    expect(screen.queryByLabelText("deployment settings")).toBeNull();
+  });
+
   it("closing a tab removes it from the tab bar", async () => {
     renderView();
     await createProject("alpha", "/home/me/alpha");

frontend/src/features/settings/DeploymentSettings.test.tsx

@@ -0,0 +1,209 @@
+/**
+ * Ticket #68 — `Settings → Deployment`, driven through the real `DIProvider`
+ * and the mock gateway (no backend).
+ *
+ * These pin the UX invariants the screen exists for, not its styling: the mode
+ * is a radio choice with consequences, the authorized-proxy field is explicitly
+ * *not* a listen address, addresses come from the backend, a refusal is
+ * actionable, and the pairing code is runtime-only.
+ */
+
+import { describe, it, expect, vi } from "vitest";
+import { render, screen, waitFor, fireEvent, within } from "@testing-library/react";
+
+import { MockDesktopServerGateway } from "@/adapters/mock";
+import type { Gateways } from "@/ports";
+import { DIProvider } from "@/app/di";
+import { DeploymentSettings } from "./DeploymentSettings";
+
+function renderView(desktopServer = new MockDesktopServerGateway()) {
+  const gateways = { desktopServer } as unknown as Gateways;
+  return {
+    desktopServer,
+    ...render(
+      <DIProvider gateways={gateways}>
+        <DeploymentSettings />
+      </DIProvider>,
+    ),
+  };
+}
+
+/** Waits past the hook's preview debounce. */
+async function settle() {
+  await screen.findByRole("radiogroup", { name: "exposure mode" });
+  await waitFor(() => expect(screen.getByLabelText("Port")).toBeTruthy());
+}
+
+function selectMode(title: string) {
+  fireEvent.click(screen.getByRole("radio", { name: new RegExp(title) }));
+}
+
+describe("DeploymentSettings", () => {
+  it("offers the three exposure modes as radio cards with their consequences", async () => {
+    renderView();
+    await settle();
+
+    const group = screen.getByRole("radiogroup", { name: "exposure mode" });
+    expect(within(group).getAllByRole("radio")).toHaveLength(3);
+
+    // The plain-language consequence is part of the choice, not a tooltip.
+    expect(
+      within(group).getByText(/Remote devices cannot connect/),
+    ).toBeTruthy();
+    expect(
+      within(group).getByText(/same machine as IdeA Desktop/),
+    ).toBeTruthy();
+    expect(
+      within(group).getByText(/only accept traffic from that proxy/),
+    ).toBeTruthy();
+  });
+
+  it("shows no exposure fields in 'This computer only'", async () => {
+    renderView();
+    await settle();
+
+    // Default is localOnly: nothing to configure, nothing to get wrong.
+    expect(screen.queryByLabelText("Public origin")).toBeNull();
+    expect(screen.queryByLabelText("Authorized proxy IP/CIDR")).toBeNull();
+    expect(screen.queryByLabelText("LAN address to bind")).toBeNull();
+  });
+
+  it("asks only for a public origin when the proxy is on this computer", async () => {
+    renderView();
+    await settle();
+    selectMode("Remote access, proxy on this computer");
+
+    expect(await screen.findByLabelText("Public origin")).toBeTruthy();
+    // The proxy is local, so there is nothing to authorize and nothing to bind.
+    expect(screen.queryByLabelText("Authorized proxy IP/CIDR")).toBeNull();
+    expect(screen.queryByLabelText("LAN address to bind")).toBeNull();
+  });
+
+  it("explains that the authorized proxy is not a listen address, and warns about the mode", async () => {
+    renderView();
+    await settle();
+    selectMode("Remote access, proxy on another machine");
+
+    // This help text is the whole point of the screen: it corrects the
+    // "that's where IdeA listens" misreading.
+    expect(
+      await screen.findByText(
+        "This is not where IdeA listens. It is the machine allowed to contact IdeA.",
+      ),
+    ).toBeTruthy();
+
+    // The permanent warning about the silent-timeout failure mode.
+    expect(
+      screen.getByText(/the proxy may time out without an IdeA error/),
+    ).toBeTruthy();
+  });
+
+  it("offers LAN addresses from the backend rather than deriving any", async () => {
+    const gateway = new MockDesktopServerGateway();
+    const preview = vi.spyOn(gateway, "previewExposure");
+    renderView(gateway);
+    await settle();
+    selectMode("Remote access, proxy on another machine");
+
+    const select = await screen.findByLabelText("LAN address to bind");
+    const offered = within(select as HTMLElement)
+      .getAllByRole("option")
+      .map((o) => (o as HTMLOptionElement).value)
+      .filter(Boolean);
+
+    // Exactly the gateway's candidates — the UI invents nothing.
+    const fromBackend = (await preview.mock.results[0]!.value).candidateLanAddresses;
+    expect(offered).toEqual(fromBackend);
+  });
+
+  it("surfaces the backend's refusal as a concrete correction", async () => {
+    renderView();
+    await settle();
+    // A remote mode with no origin: the backend says exactly what to fix.
+    selectMode("Remote access, proxy on this computer");
+
+    const alert = await screen.findByRole("alert");
+    expect(alert.textContent).toMatch(/requires publicOrigin/);
+  });
+
+  it("shows the upstream to paste, read-only, once the config is valid", async () => {
+    renderView();
+    await settle();
+    selectMode("Remote access, proxy on this computer");
+    fireEvent.change(await screen.findByLabelText("Public origin"), {
+      target: { value: "https://idea.example.com" },
+    });
+
+    const upstream = await screen.findByRole("button", {
+      name: "copy upstream url",
+    });
+    expect(upstream).toBeTruthy();
+    // The upstream is IdeA-provided, never a field the user edits.
+    expect(screen.queryByRole("textbox", { name: /upstream/i })).toBeNull();
+  });
+
+  it("keeps the pairing code runtime-only: absent until running, gone after stop", async () => {
+    renderView();
+    await settle();
+
+    expect(
+      screen.getByText("Start the server to generate a pairing code."),
+    ).toBeTruthy();
+    expect(screen.queryByRole("button", { name: "copy pairing code" })).toBeNull();
+
+    fireEvent.click(screen.getByRole("button", { name: "Start" }));
+
+    expect(
+      await screen.findByRole("button", { name: "copy pairing code" }),
+    ).toBeTruthy();
+    expect(
+      screen.getByText(/Temporary code. It disappears when the server stops/),
+    ).toBeTruthy();
+
+    fireEvent.click(screen.getByRole("button", { name: "Stop" }));
+    await waitFor(() =>
+      expect(
+        screen.getByText("Start the server to generate a pairing code."),
+      ).toBeTruthy(),
+    );
+  });
+
+  it("starts the server and reports the local URL", async () => {
+    renderView();
+    await settle();
+    fireEvent.click(screen.getByRole("button", { name: "Start" }));
+
+    await waitFor(() => expect(screen.getByText("Running")).toBeTruthy());
+    expect(screen.getByText(/Local URL:/)).toBeTruthy();
+  });
+
+  it("persists the draft before starting, so what runs is what is shown", async () => {
+    const gateway = new MockDesktopServerGateway();
+    const save = vi.spyOn(gateway, "saveExposureSettings");
+    renderView(gateway);
+    await settle();
+
+    fireEvent.change(screen.getByLabelText("Port"), { target: { value: "18080" } });
+    fireEvent.click(screen.getByRole("button", { name: "Start" }));
+
+    await waitFor(() => expect(save).toHaveBeenCalled());
+    expect(save.mock.calls[0]![0]).toMatchObject({ port: 18080 });
+    await waitFor(() =>
+      expect(screen.getByText("http://127.0.0.1:18080")).toBeTruthy(),
+    );
+  });
+
+  it("reports a failed start with the backend message", async () => {
+    const gateway = new MockDesktopServerGateway();
+    renderView(gateway);
+    await settle();
+
+    gateway.setStatus({
+      state: "failed",
+      error: { code: "INVALID", message: "port 17373 already in use" },
+    });
+
+    await waitFor(() => expect(screen.getByText("Failed")).toBeTruthy());
+    expect(screen.getByRole("alert").textContent).toMatch(/already in use/);
+  });
+});

frontend/src/features/settings/DeploymentSettings.tsx

@@ -0,0 +1,355 @@
+/**
+ * `Settings → Deployment` (ticket #68) — turn IdeA Desktop into a server other
+ * devices can reach, without a command line.
+ *
+ * Pure presentation over {@link useDeployment}; no `invoke()`, and no address is
+ * ever derived here — LAN candidates and the upstream URL come from the backend
+ * preview (`DesktopServerGateway`).
+ *
+ * Two UX invariants this screen exists to protect:
+ *
+ * - **The exposure mode is a decision, not a setting.** It is rendered as radio
+ *   *cards* with plain-language consequences, never a technical select, because
+ *   choosing wrong (proxy elsewhere, mode "on this computer") fails as a silent
+ *   proxy timeout with no IdeA error to read.
+ * - **The authorized-proxy field is not a listen address.** That confusion is
+ *   the whole reason this screen is worded the way it is; the help text under
+ *   the field says so explicitly.
+ *
+ * The pairing code is runtime-only: shown while running, never rendered into a
+ * persisted field, never mixed with the upstream value.
+ */
+
+import { useState } from "react";
+
+import type { ServerExposureMode } from "@/domain";
+import { Button, Field, Input, Panel, cn } from "@/shared";
+import { useDeployment } from "./useDeployment";
+
+interface ModeOption {
+  mode: ServerExposureMode;
+  title: string;
+  description: string;
+}
+
+/** The three exposure choices, in increasing order of reach. */
+const MODE_OPTIONS: ModeOption[] = [
+  {
+    mode: "localOnly",
+    title: "This computer only",
+    description:
+      "For using IdeA on this desktop only. Remote devices cannot connect.",
+  },
+  {
+    mode: "remoteProxyLocal",
+    title: "Remote access, proxy on this computer",
+    description:
+      "Use this when your HTTPS proxy runs on the same machine as IdeA Desktop.",
+  },
+  {
+    mode: "remoteProxyOtherMachine",
+    title: "Remote access, proxy on another machine",
+    description:
+      "Use this when the HTTPS proxy runs on another machine. IdeA will only accept traffic from that proxy.",
+  },
+];
+
+const STATE_LABEL: Record<string, string> = {
+  stopped: "Stopped",
+  starting: "Starting…",
+  running: "Running",
+  stopping: "Stopping…",
+  failed: "Failed",
+};
+
+/** Copy-to-clipboard button; degrades to disabled where the API is absent. */
+function CopyButton({ value, label }: { value: string; label: string }) {
+  const [copied, setCopied] = useState(false);
+  const supported =
+    typeof navigator !== "undefined" && Boolean(navigator.clipboard);
+  return (
+    <Button
+      size="sm"
+      variant="ghost"
+      aria-label={label}
+      disabled={!supported}
+      onClick={() => {
+        void navigator.clipboard.writeText(value).then(
+          () => {
+            setCopied(true);
+            window.setTimeout(() => setCopied(false), 1500);
+          },
+          () => setCopied(false),
+        );
+      }}
+    >
+      {copied ? "Copied" : "Copy"}
+    </Button>
+  );
+}
+
+/** A read-only value the user is meant to copy elsewhere (never editable). */
+function ReadOnlyValue({ value, copyLabel }: { value: string; copyLabel: string }) {
+  return (
+    <div className="flex items-center gap-2">
+      <code className="flex-1 truncate rounded-md border border-border bg-raised px-2 py-1.5 font-mono text-xs text-content">
+        {value}
+      </code>
+      <CopyButton value={value} label={copyLabel} />
+    </div>
+  );
+}
+
+export function DeploymentSettings() {
+  const vm = useDeployment();
+
+  if (!vm.ready || !vm.settings) {
+    return (
+      <Panel aria-label="deployment settings" title="Deployment">
+        <p className="text-sm text-muted">Loading…</p>
+      </Panel>
+    );
+  }
+
+  const { settings, status } = vm;
+  const running = status.state === "running";
+  const remote = settings.mode !== "localOnly";
+  const otherMachine = settings.mode === "remoteProxyOtherMachine";
+  const transitioning = status.state === "starting" || status.state === "stopping";
+
+  return (
+    <div aria-label="deployment settings" className="flex flex-col gap-4">
+      {/* ── Status ────────────────────────────────────────────────────────── */}
+      <Panel
+        title="Server"
+        actions={
+          running || status.state === "stopping" ? (
+            <Button
+              size="sm"
+              onClick={() => void vm.stop()}
+              disabled={vm.busy || transitioning}
+            >
+              Stop
+            </Button>
+          ) : (
+            <Button
+              size="sm"
+              onClick={() => void vm.start()}
+              disabled={vm.busy || transitioning}
+            >
+              Start
+            </Button>
+          )
+        }
+      >
+        <div className="flex flex-col gap-2">
+          <p className="flex items-center gap-2 text-sm">
+            <span
+              aria-hidden
+              className={cn(
+                "size-2 rounded-full",
+                running && "bg-success",
+                status.state === "failed" && "bg-danger",
+                (status.state === "stopped" || transitioning) && "bg-faint",
+              )}
+            />
+            <span className="text-content">{STATE_LABEL[status.state]}</span>
+          </p>
+
+          {status.localUrl && (
+            <p className="text-xs text-muted">
+              Local URL: <code className="font-mono text-content">{status.localUrl}</code>
+            </p>
+          )}
+          {status.publicUrl && (
+            <p className="text-xs text-muted">
+              Public URL: <code className="font-mono text-content">{status.publicUrl}</code>
+            </p>
+          )}
+
+          {/* A failure carries the backend's message: it is the correction. */}
+          {status.state === "failed" && status.error && (
+            <p role="alert" className="text-sm text-danger">
+              {status.error.message}
+            </p>
+          )}
+          {vm.actionError && (
+            <p role="alert" className="text-sm text-danger">
+              {vm.actionError}
+            </p>
+          )}
+        </div>
+      </Panel>
+
+      {/* ── Exposure ──────────────────────────────────────────────────────── */}
+      <Panel title="Exposure">
+        <div className="flex flex-col gap-4">
+          <div
+            role="radiogroup"
+            aria-label="exposure mode"
+            className="flex flex-col gap-2"
+          >
+            {MODE_OPTIONS.map((option) => {
+              const selected = settings.mode === option.mode;
+              return (
+                <label
+                  key={option.mode}
+                  className={cn(
+                    "flex cursor-pointer gap-3 rounded-lg border p-3 transition-colors",
+                    selected
+                      ? "border-border-strong bg-raised"
+                      : "border-border hover:bg-raised",
+                  )}
+                >
+                  <input
+                    type="radio"
+                    name="exposure-mode"
+                    className="mt-1"
+                    checked={selected}
+                    onChange={() => vm.setMode(option.mode)}
+                  />
+                  <span className="flex flex-col gap-1">
+                    <span className="text-sm font-semibold text-content">
+                      {option.title}
+                    </span>
+                    <span className="text-xs text-muted">{option.description}</span>
+                  </span>
+                </label>
+              );
+            })}
+          </div>
+
+          <Field label="Port">
+            {({ id }) => (
+              <Input
+                id={id}
+                type="number"
+                value={String(settings.port)}
+                onChange={(e) => vm.setPort(Number(e.target.value))}
+              />
+            )}
+          </Field>
+
+          {remote && (
+            <Field label="Public origin" hint="Example: https://idea.example.com">
+              {({ id, describedBy }) => (
+                <Input
+                  id={id}
+                  aria-describedby={describedBy}
+                  placeholder="https://idea.example.com"
+                  value={settings.publicOrigin ?? ""}
+                  onChange={(e) => vm.setPublicOrigin(e.target.value)}
+                />
+              )}
+            </Field>
+          )}
+
+          {otherMachine && (
+            <>
+              {/* Addresses come from the backend probe — never invented here. */}
+              <Field
+                label="LAN address to bind"
+                hint="The address on this machine that the proxy will connect to."
+              >
+                {({ id, describedBy }) =>
+                  vm.candidateLanAddresses.length > 0 ? (
+                    <select
+                      id={id}
+                      aria-describedby={describedBy}
+                      className="rounded-md border border-border bg-surface px-2 py-1.5 text-sm text-content"
+                      value={settings.lanBindAddress ?? ""}
+                      onChange={(e) => vm.setLanBindAddress(e.target.value)}
+                    >
+                      <option value="">Select an address…</option>
+                      {vm.candidateLanAddresses.map((address) => (
+                        <option key={address} value={address}>
+                          {address}
+                        </option>
+                      ))}
+                    </select>
+                  ) : (
+                    <Input
+                      id={id}
+                      aria-describedby={describedBy}
+                      placeholder="192.168.1.42"
+                      value={settings.lanBindAddress ?? ""}
+                      onChange={(e) => vm.setLanBindAddress(e.target.value)}
+                    />
+                  )
+                }
+              </Field>
+
+              <Field
+                label="Authorized proxy IP/CIDR"
+                hint="This is not where IdeA listens. It is the machine allowed to contact IdeA."
+              >
+                {({ id, describedBy }) => (
+                  <Input
+                    id={id}
+                    aria-describedby={describedBy}
+                    placeholder="203.0.113.7 or 203.0.113.0/24"
+                    value={settings.trustedProxies.join(", ")}
+                    onChange={(e) => vm.setTrustedProxies(e.target.value)}
+                  />
+                )}
+              </Field>
+
+              <p className="rounded-md border border-warning/40 bg-warning/10 px-3 py-2 text-xs text-warning">
+                If your proxy is not on this computer, choose this mode.
+                Otherwise the proxy may time out without an IdeA error.
+              </p>
+            </>
+          )}
+
+          {/* Warnings inform; they never block a start. */}
+          {vm.warnings.map((warning) => (
+            <p key={warning.code} className="text-xs text-warning">
+              {warning.message}
+            </p>
+          ))}
+
+          {vm.validationError && (
+            <p role="alert" className="text-sm text-danger">
+              {vm.validationError}
+            </p>
+          )}
+        </div>
+      </Panel>
+
+      {/* ── Proxy setup: the upstream to paste, backend-provided ──────────── */}
+      {remote && (
+        <Panel title="Proxy setup">
+          <div className="flex flex-col gap-2">
+            <p className="text-xs text-muted">
+              Point your HTTPS reverse proxy at this upstream.
+            </p>
+            {vm.upstreamUrl ? (
+              <ReadOnlyValue value={vm.upstreamUrl} copyLabel="copy upstream url" />
+            ) : (
+              <p className="text-xs text-faint">
+                Complete the settings above to get the upstream URL.
+              </p>
+            )}
+          </div>
+        </Panel>
+      )}
+
+      {/* ── Pairing: runtime-only secret, isolated from the upstream ──────── */}
+      <Panel title="Pairing">
+        {running && status.pairingCode ? (
+          <div className="flex flex-col gap-2">
+            <ReadOnlyValue value={status.pairingCode} copyLabel="copy pairing code" />
+            <p className="text-xs text-muted">
+              Temporary code. It disappears when the server stops. Do not save it
+              in configuration files.
+            </p>
+          </div>
+        ) : (
+          <p className="text-sm text-muted">
+            Start the server to generate a pairing code.
+          </p>
+        )}
+      </Panel>
+    </div>
+  );
+}

frontend/src/features/settings/SettingsView.tsx

@@ -0,0 +1,85 @@
+/**
+ * `SettingsView` — the Settings surface shell (ticket #68).
+ *
+ * Settings is a **main surface**, not a dockable project view: it deliberately
+ * has no `PanelId` and stays outside the `viewPlacement` model. It takes over
+ * the main area while the menu bar stays visible above it.
+ *
+ * Ticket #68 gives it a second section, so the section list becomes real
+ * navigation (a left column) instead of the old single toggle. That also kills
+ * the alternating "Close AI Profiles" menu label, which never scaled past one
+ * entry: the menu now names sections, the active one is marked, and closing is
+ * an explicit action inside the view.
+ *
+ * `EmbedderSettings` / `ModelServersPanel` are **not** pulled in here — that is
+ * a separate lateral rework. The section list is the seam they would slot into.
+ */
+
+import { Button, cn } from "@/shared";
+import { ProfilesSettings } from "@/features/first-run";
+import { DeploymentSettings } from "./DeploymentSettings";
+
+/** The Settings sections, in menu/nav order. */
+export type SettingsSection = "aiProfiles" | "deployment";
+
+/** Human labels, shared by the nav column and the `Settings` menu. */
+export const SETTINGS_SECTION_LABEL: Record<SettingsSection, string> = {
+  aiProfiles: "AI Profiles",
+  deployment: "Deployment",
+};
+
+/** Section order — the single source of truth for both nav and menu. */
+export const SETTINGS_SECTIONS: SettingsSection[] = ["aiProfiles", "deployment"];
+
+interface SettingsViewProps {
+  section: SettingsSection;
+  onSectionChange: (section: SettingsSection) => void;
+  onClose: () => void;
+}
+
+export function SettingsView({
+  section,
+  onSectionChange,
+  onClose,
+}: SettingsViewProps) {
+  return (
+    <div className="flex min-h-0 flex-1 overflow-hidden">
+      <nav
+        aria-label="settings sections"
+        className="flex w-52 shrink-0 flex-col gap-1 border-r border-border p-3"
+      >
+        {SETTINGS_SECTIONS.map((id) => {
+          const active = id === section;
+          return (
+            <button
+              key={id}
+              type="button"
+              aria-current={active ? "page" : undefined}
+              onClick={() => onSectionChange(id)}
+              className={cn(
+                "rounded-md px-3 py-2 text-left text-sm transition-colors",
+                active
+                  ? "bg-raised font-semibold text-content"
+                  : "text-muted hover:bg-raised hover:text-content",
+              )}
+            >
+              {SETTINGS_SECTION_LABEL[id]}
+            </button>
+          );
+        })}
+
+        <div className="mt-auto pt-2">
+          <Button size="sm" variant="ghost" className="w-full" onClick={onClose}>
+            Close Settings
+          </Button>
+        </div>
+      </nav>
+
+      <div className="flex flex-1 justify-center overflow-y-auto p-6">
+        <div className="w-full max-w-2xl">
+          {section === "aiProfiles" ? <ProfilesSettings /> : <DeploymentSettings />}
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/src/features/settings/desktop-only.test.ts

@@ -0,0 +1,60 @@
+/**
+ * Ticket #68 — "Desktop only" is a code/test guard, not just a claim.
+ *
+ * The web client never mounts `ProjectsView` (it routes through `features/web`),
+ * so the Deployment surface is unreachable there *today*. This pins that: the
+ * web feature must not import the settings surface, and the web transport must
+ * refuse the embedded-server port rather than reach for Tauri (absent on web).
+ */
+
+import { describe, it, expect } from "vitest";
+import { readdirSync, readFileSync, statSync } from "node:fs";
+import { join } from "node:path";
+
+import { WebDesktopServerGateway } from "@/adapters/http/unsupported";
+import type { GatewayError } from "@/domain";
+
+const WEB_FEATURE_DIR = join(process.cwd(), "src", "features", "web");
+
+function collectSourceFiles(dir: string, out: string[] = []): string[] {
+  for (const entry of readdirSync(dir)) {
+    const full = join(dir, entry);
+    if (statSync(full).isDirectory()) collectSourceFiles(full, out);
+    else if (/\.tsx?$/.test(entry)) out.push(full);
+  }
+  return out;
+}
+
+describe("the Deployment surface is desktop-only", () => {
+  it("features/web does not import the settings surface", () => {
+    const offenders = collectSourceFiles(WEB_FEATURE_DIR).filter((file) =>
+      /@\/features\/settings/.test(readFileSync(file, "utf8")),
+    );
+    expect(offenders, `offending files: ${offenders.join(", ")}`).toEqual([]);
+  });
+
+  it("the web transport refuses the embedded-server port", async () => {
+    const gateway = new WebDesktopServerGateway();
+
+    // Every real operation fails explicitly, with a stable code the UI can branch on.
+    for (const call of [
+      () => gateway.getExposureSettings(),
+      () => gateway.status(),
+      () => gateway.start(),
+      () => gateway.stop(),
+      () => gateway.saveExposureSettings({ mode: "localOnly", port: 0, trustedProxies: [] }),
+      () => gateway.previewExposure({ mode: "localOnly", port: 0, trustedProxies: [] }),
+    ]) {
+      const error: Partial<GatewayError> = { code: "UNSUPPORTED_ON_WEB" };
+      await expect(call()).rejects.toMatchObject(error);
+    }
+  });
+
+  it("web status subscription is inert rather than throwing", async () => {
+    // Teardown must stay callable: consumers unsubscribe unconditionally.
+    const unsubscribe = await new WebDesktopServerGateway().onStatusChanged(() => {
+      throw new Error("must never fire on web");
+    });
+    expect(() => unsubscribe()).not.toThrow();
+  });
+});

frontend/src/features/settings/index.ts

@@ -0,0 +1,11 @@
+/** Settings surface (ticket #68): section shell + the Deployment screen. */
+
+export {
+  SettingsView,
+  SETTINGS_SECTIONS,
+  SETTINGS_SECTION_LABEL,
+  type SettingsSection,
+} from "./SettingsView";
+export { DeploymentSettings } from "./DeploymentSettings";
+export { useDeployment } from "./useDeployment";
+export type { DeploymentVm } from "./useDeployment";

frontend/src/features/settings/useDeployment.ts

@@ -0,0 +1,253 @@
+/**
+ * `useDeployment` — view-model for `Settings → Deployment` (ticket #68).
+ *
+ * Owns the draft exposure config, the backend-derived preview, and the embedded
+ * server lifecycle. All behaviour lives here so `DeploymentSettings` stays
+ * presentation-only (no `invoke()`, no network reasoning in JSX).
+ *
+ * **The backend owns every network fact.** LAN candidates and the proxy upstream
+ * URL are read from `previewExposure`; nothing here derives an address.
+ *
+ * Two backend behaviours shape this hook:
+ *
+ * 1. `preview_server_exposure_settings` *validates* before previewing, so an
+ *    incomplete draft is rejected rather than previewed. That makes it the
+ *    UI's validation authority (it returns the same message `start` would), but
+ *    it also means a `remoteProxyOtherMachine` draft cannot be previewed until
+ *    it already carries a LAN bind address — which is what the preview is for.
+ *    So the LAN candidate list is fetched with a separate always-valid
+ *    `localOnly` probe; the backend builds that list independently of the mode.
+ * 2. Only `start` reports a runtime failure, so a rejected save/start surfaces
+ *    the backend message verbatim — it is the concrete correction to apply.
+ */
+
+import { useCallback, useEffect, useRef, useState } from "react";
+
+import type {
+  DiagnosticWarning,
+  EmbeddedServerStatus,
+  GatewayError,
+  ServerExposureMode,
+  ServerExposureSettings,
+} from "@/domain";
+import { useGateways } from "@/app/di";
+
+/** Debounce before previewing a draft, so typing doesn't spam the backend. */
+const PREVIEW_DEBOUNCE_MS = 250;
+
+function messageOf(e: unknown): string {
+  return e && typeof e === "object" && "message" in e
+    ? String((e as GatewayError).message)
+    : String(e);
+}
+
+export interface DeploymentVm {
+  /** False until the persisted settings have loaded. */
+  ready: boolean;
+  /** The draft config being edited (persisted config until the user edits). */
+  settings: ServerExposureSettings | null;
+  /** Current server status. */
+  status: EmbeddedServerStatus;
+  /** LAN addresses discovered by the backend (never derived client-side). */
+  candidateLanAddresses: string[];
+  /** Backend-built upstream URL for the current draft; absent when invalid. */
+  upstreamUrl?: string;
+  /** Non-fatal diagnostics for the draft — informational, never blocking. */
+  warnings: DiagnosticWarning[];
+  /** Why the draft is rejected, as told by the backend. Actionable, not decorative. */
+  validationError: string | null;
+  /** Last save/start/stop failure. */
+  actionError: string | null;
+  /** True while a start/stop is in flight. */
+  busy: boolean;
+  setMode: (mode: ServerExposureMode) => void;
+  setPublicOrigin: (origin: string) => void;
+  setLanBindAddress: (address: string) => void;
+  setTrustedProxies: (raw: string) => void;
+  setPort: (port: number) => void;
+  /** Persists the draft, then starts the server so what runs is what is shown. */
+  start: () => Promise<void>;
+  stop: () => Promise<void>;
+}
+
+export function useDeployment(): DeploymentVm {
+  const { desktopServer } = useGateways();
+  const [settings, setSettings] = useState<ServerExposureSettings | null>(null);
+  const [status, setStatus] = useState<EmbeddedServerStatus>({
+    state: "stopped",
+  });
+  const [candidateLanAddresses, setCandidates] = useState<string[]>([]);
+  const [upstreamUrl, setUpstreamUrl] = useState<string | undefined>();
+  const [warnings, setWarnings] = useState<DiagnosticWarning[]>([]);
+  const [validationError, setValidationError] = useState<string | null>(null);
+  const [actionError, setActionError] = useState<string | null>(null);
+  const [busy, setBusy] = useState(false);
+  // Guards against a stale in-flight preview overwriting a newer one.
+  const previewSeq = useRef(0);
+
+  useEffect(() => {
+    let alive = true;
+    void (async () => {
+      try {
+        const [persisted, current] = await Promise.all([
+          desktopServer.getExposureSettings(),
+          desktopServer.status(),
+        ]);
+        if (!alive) return;
+        setSettings(persisted);
+        setStatus(current);
+      } catch (e) {
+        if (alive) setActionError(messageOf(e));
+      }
+    })();
+    return () => {
+      alive = false;
+    };
+  }, [desktopServer]);
+
+  // LAN candidates via an always-valid `localOnly` probe (see the header note).
+  useEffect(() => {
+    let alive = true;
+    void (async () => {
+      try {
+        const preview = await desktopServer.previewExposure({
+          mode: "localOnly",
+          port: 0,
+          trustedProxies: [],
+        });
+        if (alive) setCandidates(preview.candidateLanAddresses);
+      } catch {
+        // No candidates ⇒ the LAN field falls back to free text; the backend
+        // still rejects a bad address on save.
+      }
+    })();
+    return () => {
+      alive = false;
+    };
+  }, [desktopServer]);
+
+  useEffect(() => {
+    let unsubscribe: (() => void) | undefined;
+    let cancelled = false;
+    void desktopServer.onStatusChanged(setStatus).then((u) => {
+      // The effect may have torn down while the subscription was resolving.
+      if (cancelled) u();
+      else unsubscribe = u;
+    });
+    return () => {
+      cancelled = true;
+      unsubscribe?.();
+    };
+  }, [desktopServer]);
+
+  // Preview (and thereby validate) the draft, debounced.
+  useEffect(() => {
+    if (!settings) return;
+    const seq = ++previewSeq.current;
+    const timer = setTimeout(() => {
+      void desktopServer.previewExposure(settings).then(
+        (preview) => {
+          if (seq !== previewSeq.current) return;
+          setUpstreamUrl(preview.upstreamUrl);
+          setWarnings(preview.warnings);
+          setValidationError(null);
+        },
+        (e) => {
+          if (seq !== previewSeq.current) return;
+          // The draft is incomplete/invalid: the backend message *is* the fix.
+          setUpstreamUrl(undefined);
+          setWarnings([]);
+          setValidationError(messageOf(e));
+        },
+      );
+    }, PREVIEW_DEBOUNCE_MS);
+    return () => clearTimeout(timer);
+  }, [desktopServer, settings]);
+
+  const patch = useCallback((change: Partial<ServerExposureSettings>) => {
+    setActionError(null);
+    setSettings((prev) => (prev ? { ...prev, ...change } : prev));
+  }, []);
+
+  const setMode = useCallback(
+    (mode: ServerExposureMode) => {
+      // Dropping to a narrower mode clears the fields that mode does not use, so
+      // a stale origin/proxy can never be persisted behind the user's back.
+      if (mode === "localOnly") {
+        patch({ mode, publicOrigin: undefined, lanBindAddress: undefined, trustedProxies: [] });
+      } else if (mode === "remoteProxyLocal") {
+        patch({ mode, lanBindAddress: undefined, trustedProxies: [] });
+      } else {
+        patch({ mode });
+      }
+    },
+    [patch],
+  );
+
+  const setPublicOrigin = useCallback(
+    (origin: string) => patch({ publicOrigin: origin.trim() || undefined }),
+    [patch],
+  );
+  const setLanBindAddress = useCallback(
+    (address: string) => patch({ lanBindAddress: address || undefined }),
+    [patch],
+  );
+  const setTrustedProxies = useCallback(
+    (raw: string) =>
+      patch({
+        trustedProxies: raw
+          .split(/[\s,]+/)
+          .map((entry) => entry.trim())
+          .filter(Boolean),
+      }),
+    [patch],
+  );
+  const setPort = useCallback((port: number) => patch({ port }), [patch]);
+
+  const start = useCallback(async () => {
+    if (!settings) return;
+    setBusy(true);
+    setActionError(null);
+    try {
+      // `start` runs the *persisted* config, so persist the draft first —
+      // otherwise the server would run something other than what is on screen.
+      await desktopServer.saveExposureSettings(settings);
+      setStatus(await desktopServer.start());
+    } catch (e) {
+      setActionError(messageOf(e));
+    } finally {
+      setBusy(false);
+    }
+  }, [desktopServer, settings]);
+
+  const stop = useCallback(async () => {
+    setBusy(true);
+    setActionError(null);
+    try {
+      setStatus(await desktopServer.stop());
+    } catch (e) {
+      setActionError(messageOf(e));
+    } finally {
+      setBusy(false);
+    }
+  }, [desktopServer]);
+
+  return {
+    ready: settings !== null,
+    settings,
+    status,
+    candidateLanAddresses,
+    upstreamUrl,
+    warnings,
+    validationError,
+    actionError,
+    busy,
+    setMode,
+    setPublicOrigin,
+    setLanBindAddress,
+    setTrustedProxies,
+    setPort,
+    start,
+    stop,
+  };
+}

frontend/src/ports/index.ts

@@ -15,6 +15,7 @@ import type {
   DomainEvent,
   EmbedderEngines,
   EmbedderProfile,
+  EmbeddedServerStatus,
   FirstRunState,
   GitBranches,
   GitCommit,
@@ -41,6 +42,8 @@ import type {
   ProfileAvailability,
   ResumableAgent,
   ReplyChunk,
+  ServerExposurePreview,
+  ServerExposureSettings,
   Skill,
   SkillScope,
   Sprint,
@@ -678,6 +681,52 @@ export interface ModelServerGateway {
   ): Promise<ModelServerCommandPreview>;
 }
 
+/**
+ * Embedded web server lifecycle + exposure settings (ticket #68). Backs the
+ * desktop `Settings → Deployment` surface, so the user can expose IdeA to
+ * remote devices without a command line.
+ *
+ * **Desktop-only.** Only the Tauri transport implements it for real; the web
+ * transport rejects (a web client is *served by* this server and must not
+ * reconfigure it). See `desktop-only.test.ts`.
+ *
+ * The backend owns every network fact: LAN candidates and the proxy upstream
+ * URL come from {@link previewExposure}, never from client-side derivation.
+ */
+export interface DesktopServerGateway {
+  /** Reads the persisted exposure settings. */
+  getExposureSettings(): Promise<ServerExposureSettings>;
+  /**
+   * Validates and persists exposure settings. Rejects with a `GatewayError`
+   * (`INVALID`) when the config is inconsistent — e.g. a remote mode without an
+   * `https://` `publicOrigin`, or `remoteProxyOtherMachine` without a concrete
+   * `lanBindAddress` / a non-empty `trustedProxies`.
+   */
+  saveExposureSettings(settings: ServerExposureSettings): Promise<void>;
+  /**
+   * Derives LAN candidates, the upstream URL and non-fatal warnings for a
+   * **draft** config, without persisting it. The single source of truth for the
+   * addresses the UI displays.
+   */
+  previewExposure(
+    settings: ServerExposureSettings,
+  ): Promise<ServerExposurePreview>;
+  /** Current server status. */
+  status(): Promise<EmbeddedServerStatus>;
+  /** Starts the server with the persisted settings; resolves with the new status. */
+  start(): Promise<EmbeddedServerStatus>;
+  /** Stops the server; resolves with the new status. */
+  stop(): Promise<EmbeddedServerStatus>;
+  /**
+   * Observes status transitions. The backend emits no status event today, so
+   * the Tauri adapter polls `embedded_server_status`; the schedule is a
+   * transport detail owned by the adapter, and callers must not depend on it.
+   */
+  onStatusChanged(
+    handler: (status: EmbeddedServerStatus) => void,
+  ): Promise<Unsubscribe>;
+}
+
 /** Input for {@link EmbedderGateway.saveEmbedderProfile}. */
 export interface SaveEmbedderProfileInput {
   profile: EmbedderProfile;
@@ -1076,6 +1125,7 @@ export interface Gateways {
   remote: RemoteGateway;
   profile: ProfileGateway;
   modelServer: ModelServerGateway;
+  desktopServer: DesktopServerGateway;
   template: TemplateGateway;
   skill: SkillGateway;
   memory: MemoryGateway;