feat(FN-3406): add shell context hook plumbing for dashboard

Adds a new `useShellContext` hook with tests to the dashboard, integrated into `App.tsx` and `Header.tsx` to provide shell context plumbing throughout the UI.

Fusion-Task-Id: FN-3406

packages/desktop/src/__tests__/ipc.test.ts

@@ -128,6 +128,7 @@ describe("ipc handlers", () => {
     expect(channels.has("desktopRuntime:startLocal")).toBe(true);
     expect(channels.has("desktopRuntime:stopLocal")).toBe(true);
     expect(channels.has("desktopLaunchMode:getMode")).toBe(true);
+    expect(channels.has("desktopLaunchMode:getContext")).toBe(true);
     expect(channels.has("desktopLaunchMode:setMode")).toBe(true);
     expect(channels.has("platform:get")).toBe(true);
   });
@@ -155,12 +156,14 @@ describe("ipc handlers", () => {
     expect(window.webContents.send).toHaveBeenCalledWith("shell:state", expect.any(Object));
   });
 
-  it("desktop launch mode handlers return mode and validate payload", async () => {
+  it("desktop launch mode handlers return mode/context and validate payload", async () => {
+    const getDesktopLaunchContext = vi.fn(() => ({ mode: "remote", profileId: "profile_1", serverBaseUrl: "https://remote.example.com" }));
     const onDesktopLaunchModeChange = vi.fn(async () => undefined);
     const getDesktopLaunchMode = vi.fn(() => "remote");
-    await registerHandlers({ onDesktopLaunchModeChange, getDesktopLaunchMode });
+    await registerHandlers({ onDesktopLaunchModeChange, getDesktopLaunchMode, getDesktopLaunchContext });
 
     await expect(mocks.ipcHandlers.get("desktopLaunchMode:getMode")?.({})).resolves.toBe("remote");
+    await expect(mocks.ipcHandlers.get("desktopLaunchMode:getContext")?.({})).resolves.toEqual({ mode: "remote", profileId: "profile_1", serverBaseUrl: "https://remote.example.com" });
     await expect(mocks.ipcHandlers.get("desktopLaunchMode:setMode")?.({}, "local")).resolves.toBe("remote");
     await expect(mocks.ipcHandlers.get("desktopLaunchMode:setMode")?.({}, "bad")).rejects.toThrow("Invalid desktop launch mode");
     expect(onDesktopLaunchModeChange).toHaveBeenCalledWith("local");

packages/desktop/src/__tests__/main-integration.test.ts

@@ -168,6 +168,11 @@ vi.mock("../native.js", () => ({
   saveWindowState: mocks.saveWindowState,
   setupAutoUpdater: mocks.setupAutoUpdater,
   DEFAULT_WINDOW_STATE: mocks.DEFAULT_WINDOW_STATE,
+  normalizeDesktopRemoteLaunch: vi.fn((settings) => {
+    const active = settings.profiles.find((profile: { id: string }) => profile.id === settings.activeProfileId);
+    return active ? { mode: "remote", profileId: active.id, serverBaseUrl: active.serverUrl.replace(/\/$/, ""), serverLabel: active.name, authToken: active.authToken ?? undefined } : null;
+  }),
+  buildRemoteShellHandoffUrl: vi.fn((launch) => `https://remote.example.com?shellMode=remote&profileId=${launch.profileId}`),
 }));
 
 vi.mock("../local-runtime.js", () => ({
@@ -180,6 +185,14 @@ vi.mock("../local-runtime.js", () => ({
 }));
 
 // Mock renderer module
+vi.mock("../shell-settings.js", () => ({
+  readShellSettings: vi.fn(async () => ({
+    desktopMode: "remote",
+    activeProfileId: "profile_1",
+    profiles: [{ id: "profile_1", name: "Remote", serverUrl: "https://remote.example.com", authToken: "token" }],
+  })),
+}));
+
 vi.mock("../renderer.js", () => ({
   isDevelopmentMode: vi.fn(() => false),
   getRendererUrl: vi.fn(() => "file:///path/to/dist/client/index.html"),
@@ -375,6 +388,17 @@ describe("main integration", () => {
     }
   });
 
+  it("loads remote handoff URL when remembered mode is remote", async () => {
+    mocks.loadDesktopLaunchMode.mockResolvedValueOnce("remote");
+    const { initializeApp } = await importMainModule();
+
+    await initializeApp();
+
+    const [{ instance }] = mocks.windowInstances;
+    expect(instance.loadURL).toHaveBeenCalledWith(expect.stringContaining("shellMode=remote"));
+    expect(mocks.startLocal).not.toHaveBeenCalled();
+  });
+
   it("starts local runtime when remembered mode is local", async () => {
     mocks.loadDesktopLaunchMode.mockResolvedValueOnce("local");
     const { initializeApp } = await importMainModule();

packages/desktop/src/__tests__/main.test.ts

@@ -137,11 +137,24 @@ vi.mock("../native.js", () => ({
   saveDesktopLaunchMode: mainDeps.saveDesktopLaunchMode,
   saveWindowState: mainDeps.saveWindowState,
   setupAutoUpdater: mainDeps.setupAutoUpdater,
+  normalizeDesktopRemoteLaunch: vi.fn((settings) => {
+    const active = settings.profiles.find((profile: { id: string }) => profile.id === settings.activeProfileId);
+    return active ? { mode: "remote", profileId: active.id, serverBaseUrl: active.serverUrl.replace(/\/$/, ""), serverLabel: active.name, authToken: active.authToken ?? undefined } : null;
+  }),
+  buildRemoteShellHandoffUrl: vi.fn((launch) => `https://remote.example.com?shellKind=desktop&shellMode=remote&profileId=${launch.profileId}`),
 }));
 vi.mock("../local-runtime.js", () => ({
   LocalRuntimeManager: mainDeps.LocalRuntimeManager,
 }));
 
+vi.mock("../shell-settings.js", () => ({
+  readShellSettings: vi.fn(async () => ({
+    desktopMode: "remote",
+    activeProfileId: "profile_1",
+    profiles: [{ id: "profile_1", name: "Remote", serverUrl: "https://remote.example.com", authToken: "token" }],
+  })),
+}));
+
 async function importMainModule() {
   return import("../main.ts");
 }
@@ -264,13 +277,16 @@ describe("main process", () => {
     expect(mainDeps.startLocal).not.toHaveBeenCalled();
   });
 
-  it("initializeApp does not start local runtime for remembered remote mode", async () => {
+  it("initializeApp routes remembered remote mode to remote dashboard handoff URL", async () => {
     mainDeps.loadDesktopLaunchMode.mockResolvedValueOnce("remote");
     const { initializeApp, getCurrentDesktopLaunchMode } = await importMainModule();
 
     await initializeApp();
 
     expect(mainDeps.startLocal).not.toHaveBeenCalled();
+    expect(mocks.browserWindowInstance.loadURL).toHaveBeenCalledWith(
+      expect.stringContaining("shellMode=remote"),
+    );
     expect(getCurrentDesktopLaunchMode()).toBe("remote");
   });
 

packages/desktop/src/__tests__/preload.test.ts

@@ -54,13 +54,16 @@ describe("preload", () => {
     await importPreloadModule();
     const api = getExposed<{
       getDesktopLaunchMode: () => Promise<string>;
+      getDesktopLaunchContext: () => Promise<unknown>;
       setDesktopLaunchMode: (mode: "choose" | "local" | "remote") => Promise<string>;
     }>("electronAPI");
 
     await api?.getDesktopLaunchMode();
+    await api?.getDesktopLaunchContext();
     await api?.setDesktopLaunchMode("local");
 
     expect(mocks.ipcRenderer.invoke).toHaveBeenCalledWith("desktopLaunchMode:getMode");
+    expect(mocks.ipcRenderer.invoke).toHaveBeenCalledWith("desktopLaunchMode:getContext");
     expect(mocks.ipcRenderer.invoke).toHaveBeenCalledWith("desktopLaunchMode:setMode", "local");
   });