feat(ui): gate the pull-request surface on GitHub, move the account into it, and GitHub sign-in into Integrations

The pull-request rail icon now appears only while GitHub is connected
(OAuth or gh CLI), like Linear; Linear sits after the walkthrough in the
default rail order. The GitHub account avatar and switcher leave the
header for the pull-request panel, where the walkthrough, refresh, and
account controls share one row and one height, and the account stays
visible on the panel's empty state. A manual refresh keeps its spinner on
screen long enough to read as work done.

GitHub sign-in moves from Settings → Git to Settings → Integrations →
Built-in integrations as a card before Linear; search and the connect
buttons follow it.

packages/ui/src/lib/surfaces/DOCUMENTATION.md

@@ -27,7 +27,9 @@ edge (`components/layout/ContextPanelRail.tsx`) and rendered by
   configure button — `ContextRailSurfacesDialog`), drops the plan surface
   unless plan mode is enabled,
   drops the walkthrough on VS Code and below `WALKTHROUGH_MIN_WIDTH`, hides
-  Linear unless a workspace is connected, and hides `has-content` surfaces
+  Linear unless a workspace is connected, hides the pull-request surface
+  unless GitHub is connected (OAuth or `gh` CLI — signed in from Settings →
+  Integrations), and hides `has-content` surfaces
   until a tab of their mode exists. Both consumers use it so the digit shown
   on a rail badge always maps to the same surface the shortcut opens.
 

packages/ui/src/lib/surfaces/registry.test.ts

@@ -13,6 +13,7 @@ const baseOptions = {
   screenWidth: 1200,
   tabs: [],
   linearConnected: true,
+  githubConnected: true,
 } as const;
 
 describe('getVisibleContextRailSurfaces', () => {
@@ -65,12 +66,16 @@ describe('getVisibleContextRailSurfaces', () => {
     expect(surfaces.slice(0, 2).map((surface) => surface.id)).toEqual(['git', 'context']);
   });
 
-  test('places Linear after Pull Request in the default order', () => {
+  test('places Linear right after the walkthrough in the default order', () => {
     const ids = getVisibleContextRailSurfaces(baseOptions).map((surface) => surface.id);
-    const pr = ids.indexOf('pr');
-    const linear = ids.indexOf('linear');
-    expect(pr).toBeGreaterThanOrEqual(0);
-    expect(linear).toBe(pr + 1);
+    const walkthrough = ids.indexOf('walkthrough');
+    expect(walkthrough).toBeGreaterThanOrEqual(0);
+    expect(ids.indexOf('linear')).toBe(walkthrough + 1);
+  });
+
+  test('hides the pull request surface until GitHub is connected', () => {
+    expect(getVisibleContextRailSurfaces({ ...baseOptions, githubConnected: false }).some((s) => s.id === 'pr')).toBe(false);
+    expect(getVisibleContextRailSurfaces({ ...baseOptions, githubConnected: true }).some((s) => s.id === 'pr')).toBe(true);
   });
 
   test('hides Linear until a workspace is connected', () => {

packages/ui/src/lib/surfaces/registry.ts

@@ -66,15 +66,6 @@ export const CONTEXT_SURFACES: readonly ContextSurfaceDescriptor[] = [
     labelKey: 'contextPanel.mode.pr',
     availability: 'always',
   },
-  {
-    id: 'linear',
-    descriptionKey: 'contextRail.surface.linear.description',
-    defaultWidthFraction: 0.45,
-    mode: 'linear',
-    icon: 'linear',
-    labelKey: 'contextPanel.mode.linear',
-    availability: 'always',
-  },
   {
     id: 'diff',
     descriptionKey: 'contextRail.surface.diff.description',
@@ -93,6 +84,15 @@ export const CONTEXT_SURFACES: readonly ContextSurfaceDescriptor[] = [
     labelKey: 'contextPanel.mode.walkthrough',
     availability: 'always',
   },
+  {
+    id: 'linear',
+    descriptionKey: 'contextRail.surface.linear.description',
+    defaultWidthFraction: 0.45,
+    mode: 'linear',
+    icon: 'linear',
+    labelKey: 'contextPanel.mode.linear',
+    availability: 'always',
+  },
   {
     id: 'editor',
     descriptionKey: 'contextRail.surface.editor.description',
@@ -206,6 +206,10 @@ type VisibleRailSurfacesOptions = {
   tabs: readonly { mode: ContextPanelMode }[];
   /** Linear's rail icon stays off until a workspace is connected. */
   linearConnected: boolean;
+  /** The pull-request rail icon stays off until GitHub is connected (OAuth
+      or a detected `gh` CLI login). GitHub is connected from Settings, so
+      hiding the surface removes no entry point. */
+  githubConnected: boolean;
 };
 
 /**
@@ -240,6 +244,9 @@ export const getVisibleContextRailSurfaces = (options: VisibleRailSurfacesOption
     if (surface.id === 'linear' && !options.linearConnected) {
       return false;
     }
+    if (surface.id === 'pr' && !options.githubConnected) {
+      return false;
+    }
     if (surface.availability === 'has-content') {
       return options.tabs.some((tab) => tab.mode === surface.mode);
     }