Flatten settings sidebar with a host picker (#1241)

* Flatten settings sidebar with a host picker

Settings had two implicit tiers: app-level sections as flat sidebar rows,
and per-host settings hidden behind a drill-in to one monolithic host page.
This flattens both into a single sidebar with an "App" group and a "Host"
group, where the host's settings are top-level rows scoped by a host picker.

- Split the monolithic HostPage into four section pages: Connections,
  Orchestration (was the unnamed inject-tools + system-prompt block),
  Providers, and Daemon (status, updates, restart, remove).
- Host picker reuses the canonical <Combobox> sidebar host switcher; defaults
  to the local host so a single-local-host user never thinks about "the daemon".
- Host sections become real sub-routes (/settings/hosts/[id]/[section]); the
  old /settings/hosts/[id] redirects to the connections section, so existing
  deep links (pairing, workspace, open-project) keep working.
- "Open providers" from the project screen now lands on the Providers section.

* Fix e2e host-settings navigation for the flat sidebar

The flat-settings refactor moved host settings onto separate section pages,
but three e2e helpers still expected the old monolithic host page:

- openDesktopSettings: the daemon-lifecycle card now lives on the Daemon
  section — navigate there before asserting it.
- acp catalog: "Add provider" now lives on the Providers section — open that
  section before opening the add-provider modal.
- openAddHostFlow: "Add host" is now an item inside the host picker (Combobox),
  not a standalone button — open the picker first.

Test-only; no product changes. Fixes the 8 playwright failures on this branch.

packages/app/e2e/settings-host-page.spec.ts

@@ -6,12 +6,14 @@ import { getServerId } from "./helpers/server-id";
 import {
   expectSettingsHeader,
   openSettingsHost,
+  openHostSection,
   expectHostLabelDisplayed,
   clickEditHostLabel,
   expectHostLabelEditMode,
   expectHostConnectionsCard,
   expectHostInjectMcpCard,
   expectHostActionCards,
+  expectHostProvidersCard,
   expectHostNoLocalOnlyRows,
   expectRetiredSidebarSectionsAbsent,
   expectHostPageVisible,
@@ -19,9 +21,7 @@ import {
 } from "./helpers/settings";
 
 test.describe("Settings host page", () => {
-  test("host page shows seeded label, connection endpoint, inject MCP toggle, and all action rows", async ({
-    page,
-  }) => {
+  test("connections section shows the seeded connection endpoint", async ({ page }) => {
     const serverId = getServerId();
     const port = getE2EDaemonPort();
 
@@ -29,11 +29,44 @@ test.describe("Settings host page", () => {
     await openSettings(page);
     await openSettingsHost(page, serverId);
 
-    await expectSettingsHeader(page, TEST_HOST_LABEL);
-    await expectHostLabelDisplayed(page);
+    await expectSettingsHeader(page, "Connections");
     await expectHostConnectionsCard(page, port);
+  });
+
+  test("orchestration section shows the inject MCP toggle", async ({ page }) => {
+    const serverId = getServerId();
+
+    await gotoAppShell(page);
+    await openSettings(page);
+    await openSettingsHost(page, serverId);
+
+    await openHostSection(page, serverId, "orchestration");
+    await expectSettingsHeader(page, "Orchestration");
     await expectHostInjectMcpCard(page);
-    await expectHostActionCards(page);
+  });
+
+  test("providers section shows the providers card", async ({ page }) => {
+    const serverId = getServerId();
+
+    await gotoAppShell(page);
+    await openSettings(page);
+    await openSettingsHost(page, serverId);
+
+    await expectHostProvidersCard(page, serverId);
+    await expectSettingsHeader(page, "Providers");
+  });
+
+  test("daemon section shows the host label and restart/remove action cards", async ({ page }) => {
+    const serverId = getServerId();
+
+    await gotoAppShell(page);
+    await openSettings(page);
+    await openSettingsHost(page, serverId);
+
+    await openHostSection(page, serverId, "daemon");
+    await expectSettingsHeader(page, "Daemon");
+    await expectHostLabelDisplayed(page);
+    await expectHostActionCards(page, serverId);
   });
 
   test("clicking the label pencil reveals the inline editor", async ({ page }) => {
@@ -42,13 +75,14 @@ test.describe("Settings host page", () => {
     await gotoAppShell(page);
     await openSettings(page);
     await openSettingsHost(page, serverId);
+    await openHostSection(page, serverId, "daemon");
 
     await expectHostLabelDisplayed(page);
     await clickEditHostLabel(page);
     await expectHostLabelEditMode(page, TEST_HOST_LABEL);
   });
 
-  test("host page does not render pair-device or daemon-lifecycle rows for a remote daemon", async ({
+  test("daemon section does not render pair-device or daemon-lifecycle rows for a remote daemon", async ({
     page,
   }) => {
     const serverId = getServerId();
@@ -56,19 +90,20 @@ test.describe("Settings host page", () => {
     await gotoAppShell(page);
     await openSettings(page);
     await openSettingsHost(page, serverId);
+    await openHostSection(page, serverId, "daemon");
 
     // TODO: add local-daemon fixture for positive Pair/Daemon coverage.
     await expectHostNoLocalOnlyRows(page);
   });
 
-  test("settings sidebar does not expose retired top-level sections", async ({ page }) => {
+  test("settings sidebar exposes the flat App and Host section rows", async ({ page }) => {
     await gotoAppShell(page);
     await openSettings(page);
 
     await expectRetiredSidebarSectionsAbsent(page);
   });
 
-  test("navigating to /settings/hosts/[serverId] directly renders the host page", async ({
+  test("navigating to /settings/hosts/[serverId] redirects to the connections section", async ({
     page,
   }) => {
     const serverId = getServerId();
@@ -77,9 +112,10 @@ test.describe("Settings host page", () => {
     await page.goto(`/settings/hosts/${encodeURIComponent(serverId)}`);
 
     await expectHostPageVisible(page, serverId);
-    await expectSettingsHeader(page, TEST_HOST_LABEL);
+    await expectSettingsHeader(page, "Connections");
+    await openHostSection(page, serverId, "daemon");
     await expectHostLabelDisplayed(page);
-    await expectHostActionCards(page);
+    await expectHostActionCards(page, serverId);
   });
 
   test("sidebar pins the local daemon host first with a Local marker", async ({ page }) => {