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/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) =>