fix(tui): resolve cross-platform root detection and fallback paths in pickers

pkg/selfupdate/exec_windows.go

@@ -27,9 +27,9 @@ func swapBinary(dst, src string) error {
 		if cpErr := atomicWriteFromFile(dst, src); cpErr != nil {
 			// Roll back so we never leave the install without a binary.
 			if rbErr := os.Rename(old, dst); rbErr != nil {
-				return fmt.Errorf("installing new binary: %w (copy fallback failed: %v; rollback also failed: %v)", err, cpErr, rbErr)
+				return fmt.Errorf("installing new binary: %w (copy fallback failed: %w; rollback also failed: %w)", err, cpErr, rbErr)
 			}
-			return fmt.Errorf("installing new binary: %w (copy fallback failed: %v)", err, cpErr)
+			return fmt.Errorf("installing new binary: %w (copy fallback failed: %w)", err, cpErr)
 		}
 		_ = os.Remove(src)
 	}
@@ -48,7 +48,7 @@ func reExecProcess(path string, args, env []string) error {
 		childArgs = args[1:]
 	}
 
-	cmd := exec.Command(path, childArgs...) //nolint:gosec // path is our own freshly installed binary
+	cmd := exec.Command(path, childArgs...) //nolint:noctx // path is our own freshly installed binary; no context needed for re-exec
 	cmd.Env = env
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout

pkg/tools/builtin/backgroundjobs/cmd_windows.go

@@ -31,13 +31,13 @@ func createProcessGroup(proc *os.Process) (*processGroup, error) {
 	if _, err := windows.SetInformationJobObject(
 		job,
 		windows.JobObjectExtendedLimitInformation,
-		uintptr(unsafe.Pointer(&info)),
+		uintptr(unsafe.Pointer(&info)), //nolint:gosec // Windows API requires unsafe pointer
 		uint32(unsafe.Sizeof(info))); err != nil {
 		_ = windows.CloseHandle(job)
 		return nil, err
 	}
 
-	handle, err := windows.OpenProcess(windows.PROCESS_SET_QUOTA|windows.PROCESS_TERMINATE, false, uint32(proc.Pid))
+	handle, err := windows.OpenProcess(windows.PROCESS_SET_QUOTA|windows.PROCESS_TERMINATE, false, uint32(proc.Pid)) //nolint:gosec // Pid is safe to convert to uint32 on Windows
 	if err != nil {
 		_ = windows.CloseHandle(job)
 		return nil, err

pkg/tools/builtin/shell/cmd_windows.go

@@ -31,13 +31,13 @@ func createProcessGroup(proc *os.Process) (*processGroup, error) {
 	if _, err := windows.SetInformationJobObject(
 		job,
 		windows.JobObjectExtendedLimitInformation,
-		uintptr(unsafe.Pointer(&info)),
+		uintptr(unsafe.Pointer(&info)), //nolint:gosec // Windows API requires unsafe pointer
 		uint32(unsafe.Sizeof(info))); err != nil {
 		_ = windows.CloseHandle(job)
 		return nil, err
 	}
 
-	handle, err := windows.OpenProcess(windows.PROCESS_SET_QUOTA|windows.PROCESS_TERMINATE, false, uint32(proc.Pid))
+	handle, err := windows.OpenProcess(windows.PROCESS_SET_QUOTA|windows.PROCESS_TERMINATE, false, uint32(proc.Pid)) //nolint:gosec // Pid is safe to convert to uint32 on Windows
 	if err != nil {
 		_ = windows.CloseHandle(job)
 		return nil, err

pkg/tui/dialog/file_picker.go

@@ -144,7 +144,7 @@ func (d *filePickerDialog) loadDirectory() {
 	d.scrollview.SetScrollOffset(0)
 	d.err = nil
 
-	if d.currentDir != "/" {
+	if filepath.Dir(d.currentDir) != d.currentDir {
 		d.entries = append(d.entries, fileEntry{
 			name:  "..",
 			path:  filepath.Dir(d.currentDir),

pkg/tui/dialog/file_picker_test.go

@@ -317,6 +317,24 @@ func TestFilePickerParentDirEntry(t *testing.T) {
 	require.Equal(t, filepath.Dir(dir), d.entries[0].path)
 }
 
+func TestFilePickerRootHasNoParentDirEntry(t *testing.T) {
+	t.Parallel()
+
+	// Get the root of the current working directory to test root behavior cross-platform
+	cwd, err := os.Getwd()
+	require.NoError(t, err)
+	root := filepath.VolumeName(cwd) + string(filepath.Separator)
+
+	d := newTestFilePickerDialog(root)
+
+	// Ensure there's no ".." entry
+	for _, e := range d.entries {
+		if e.name == ".." {
+			t.Errorf("root directory should not have a parent dir entry, but got '..'")
+		}
+	}
+}
+
 func TestFilePickerFilterPreservesParentDir(t *testing.T) {
 	t.Parallel()
 	dir := setupTestDir(t)

pkg/tui/dialog/working_dir_picker.go

@@ -168,7 +168,7 @@ func NewWorkingDirPickerDialog(ctx context.Context, recentDirs, favoriteDirs []s
 		var err error
 		cwd, err = os.Getwd()
 		if err != nil {
-			cwd = "/"
+			cwd = "."
 		}
 	}
 
@@ -258,7 +258,7 @@ func (d *workingDirPickerDialog) loadBrowseDirectory() {
 		kind: entryUseThisDir,
 	})
 
-	if d.currentDir != "/" {
+	if filepath.Dir(d.currentDir) != d.currentDir {
 		d.browseEntries = append(d.browseEntries, dirEntry{
 			name: "..",
 			path: filepath.Dir(d.currentDir),

pkg/tui/dialog/working_dir_picker_test.go

@@ -0,0 +1,40 @@
+package dialog
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestWorkingDirPickerRootHasNoParentDirEntry(t *testing.T) {
+	t.Parallel()
+
+	// Get the root of the current working directory
+	cwd, err := os.Getwd()
+	require.NoError(t, err)
+	root := filepath.VolumeName(cwd) + string(filepath.Separator)
+
+	d := NewWorkingDirPickerDialog(t.Context(), nil, nil, nil, root).(*workingDirPickerDialog)
+
+	// Ensure there's no ".." entry in the browse entries
+	for _, e := range d.browseEntries {
+		if e.name == ".." {
+			t.Errorf("root directory should not have a parent dir entry, but got '..'")
+		}
+	}
+}
+
+func TestWorkingDirPickerEmptyFallback(t *testing.T) {
+	t.Parallel()
+
+	// Pass an empty string for the initial directory.
+	// NewWorkingDirPickerDialog should fall back to os.Getwd().
+	d := NewWorkingDirPickerDialog(t.Context(), nil, nil, nil, "").(*workingDirPickerDialog)
+
+	cwd, err := os.Getwd()
+	require.NoError(t, err)
+
+	require.Equal(t, cwd, d.currentDir, "empty initial directory should fall back to current working directory")
+}

pkg/tui/tui.go

@@ -2159,7 +2159,7 @@ func (m *appModel) handleCloseTab(sessionID string) (tea.Model, tea.Cmd) {
 			workingDir, _ = os.Getwd()
 		}
 		if workingDir == "" {
-			workingDir = "/"
+			workingDir = "."
 		}
 		return m.handleSpawnSession(workingDir)
 	}