feat(04-01): wire ContextSwitcher into SidebarHeader and add keyboard shortcut

- Add ContextSwitcher to SidebarHeader Row 1 with visual separator
- Add Cmd+Shift+K shortcut to cycle through available contexts
- Add SSH status listener in App.tsx to refresh context list on changes
- Shortcut guard: disabled during active context switch

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/renderer/App.tsx

@@ -24,6 +24,15 @@ export const App = (): React.JSX.Element => {
     void useStore.getState().initializeContextSystem();
   }, []);
 
+  // Refresh available contexts when SSH connection state changes
+  useEffect(() => {
+    if (!window.electronAPI.ssh?.onStatus) return;
+    const cleanup = window.electronAPI.ssh.onStatus(() => {
+      void useStore.getState().fetchAvailableContexts();
+    });
+    return cleanup;
+  }, []);
+
   // Initialize IPC event listeners (notifications, file changes)
   useEffect(() => {
     const cleanup = initializeNotificationListeners();

src/renderer/components/layout/SidebarHeader.tsx

@@ -19,6 +19,7 @@ import { truncateMiddle } from '@renderer/utils/stringUtils';
 import { Check, ChevronDown, GitBranch, PanelLeft } from 'lucide-react';
 import { useShallow } from 'zustand/react/shallow';
 
+import { ContextSwitcher } from '../common/ContextSwitcher';
 import { WorktreeBadge } from '../common/WorktreeBadge';
 
 import type { Worktree, WorktreeSource } from '@renderer/types/data';
@@ -325,7 +326,7 @@ export const SidebarHeader = (): React.JSX.Element => {
       {/* ROW 1: Project Identity (Title Bar / Drag Region) */}
       <div
         ref={projectDropdownRef}
-        className="relative flex select-none items-center justify-between pr-2"
+        className="relative flex select-none items-center gap-2 pr-2"
         style={
           {
             height: `${HEADER_ROW1_HEIGHT}px`,
@@ -334,6 +335,16 @@ export const SidebarHeader = (): React.JSX.Element => {
           } as React.CSSProperties
         }
       >
+        {/* Context Switcher - workspace indicator */}
+        <ContextSwitcher />
+
+        {/* Visual separator */}
+        <div
+          className="h-4 w-px"
+          style={{ backgroundColor: 'var(--color-border)' }}
+        />
+
+        {/* Project name dropdown button */}
         <button
           onClick={() => setIsProjectDropdownOpen(!isProjectDropdownOpen)}
           className="flex min-w-0 items-center gap-2 transition-opacity hover:opacity-80"
@@ -356,7 +367,7 @@ export const SidebarHeader = (): React.JSX.Element => {
           onClick={toggleSidebar}
           onMouseEnter={() => setIsCollapseHovered(true)}
           onMouseLeave={() => setIsCollapseHovered(false)}
-          className="shrink-0 rounded-md p-1.5 transition-colors"
+          className="ml-auto shrink-0 rounded-md p-1.5 transition-colors"
           style={
             {
               WebkitAppRegion: 'no-drag',

src/renderer/hooks/useKeyboardShortcuts.ts

@@ -38,6 +38,10 @@ export function useKeyboardShortcuts(): void {
     focusPane,
     splitPane,
     closePane,
+    availableContexts,
+    activeContextId,
+    switchContext,
+    isContextSwitching,
   } = useStore(
     useShallow((s) => ({
       openTabs: s.openTabs,
@@ -61,6 +65,10 @@ export function useKeyboardShortcuts(): void {
       focusPane: s.focusPane,
       splitPane: s.splitPane,
       closePane: s.closePane,
+      availableContexts: s.availableContexts,
+      activeContextId: s.activeContextId,
+      switchContext: s.switchContext,
+      isContextSwitching: s.isContextSwitching,
     }))
   );
 
@@ -205,6 +213,17 @@ export function useKeyboardShortcuts(): void {
         return;
       }
 
+      // Cmd+Shift+K: Cycle to next workspace context
+      if (event.key === 'k' && event.shiftKey) {
+        event.preventDefault();
+        if (!isContextSwitching && availableContexts.length > 1) {
+          const currentIndex = availableContexts.findIndex((c) => c.id === activeContextId);
+          const nextIndex = (currentIndex + 1) % availableContexts.length;
+          void switchContext(availableContexts[nextIndex].id);
+        }
+        return;
+      }
+
       // Cmd+K: Open command palette for global search
       if (event.key === 'k') {
         event.preventDefault();
@@ -280,5 +299,9 @@ export function useKeyboardShortcuts(): void {
     focusPane,
     splitPane,
     closePane,
+    availableContexts,
+    activeContextId,
+    switchContext,
+    isContextSwitching,
   ]);
 }