feat: make MCP restore command always available in Cmd+K

The "Install MCP Server" command was only enabled when status was
"not_installed", preventing users from re-registering when MCP got
removed or broken. Now the command is always available:
- Shows "Install MCP Server" when not installed
- Shows "Restore MCP Server" when already installed
- Added restore/fix/repair keywords for discoverability
- Context-aware toast: "installed" vs "restored"
- Menu bar label updated to "Restore MCP Server"

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

src/hooks/useCommandRegistry.test.ts

@@ -197,6 +197,64 @@ describe('groupSortKey', () => {
   })
 })
 
+describe('install-mcp command', () => {
+  it('is enabled when mcpStatus is not_installed and handler provided', () => {
+    const config = makeConfig({ mcpStatus: 'not_installed', onInstallMcp: vi.fn() })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    expect(cmd).toBeDefined()
+    expect(cmd!.enabled).toBe(true)
+    expect(cmd!.label).toBe('Install MCP Server')
+  })
+
+  it('is enabled when mcpStatus is installed and handler provided (restore use case)', () => {
+    const config = makeConfig({ mcpStatus: 'installed', onInstallMcp: vi.fn() })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    expect(cmd!.enabled).toBe(true)
+    expect(cmd!.label).toBe('Restore MCP Server')
+  })
+
+  it('is disabled when mcpStatus is checking', () => {
+    const config = makeConfig({ mcpStatus: 'checking', onInstallMcp: vi.fn() })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    expect(cmd!.enabled).toBe(false)
+  })
+
+  it('is disabled when no handler provided', () => {
+    const config = makeConfig({ mcpStatus: 'not_installed' })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    expect(cmd!.enabled).toBe(false)
+  })
+
+  it('has restore keyword for discoverability', () => {
+    const config = makeConfig({ mcpStatus: 'installed', onInstallMcp: vi.fn() })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    expect(cmd!.keywords).toContain('restore')
+    expect(cmd!.keywords).toContain('mcp')
+    expect(cmd!.keywords).toContain('claude')
+  })
+
+  it('executes onInstallMcp callback', () => {
+    const onInstallMcp = vi.fn()
+    const config = makeConfig({ mcpStatus: 'installed', onInstallMcp })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    cmd!.execute()
+    expect(onInstallMcp).toHaveBeenCalled()
+  })
+
+  it('is in Settings group', () => {
+    const config = makeConfig({ mcpStatus: 'installed', onInstallMcp: vi.fn() })
+    const { result } = renderHook(() => useCommandRegistry(config))
+    const cmd = findCommand(result.current, 'install-mcp')
+    expect(cmd!.group).toBe('Settings')
+  })
+})
+
 describe('buildTypeCommands', () => {
   it('creates new and list commands for each type', () => {
     const onCreateNoteOfType = vi.fn()