feat(ui): type the namespace when the cluster does not list them (#84)

Some users cannot list namespaces on a cluster. The add wizard showed
an error and offered no way forward.

The namespace step now switches to a text prompt when the list call
fails or returns nothing. The prompt shows the reason and checks that
the name is a valid DNS label. Esc from a later step returns to the
prompt.

The j and k keys now type into text fields. They moved the list cursor
before, so a name such as kube-system could not be typed.

Closes #66

internal/ui/wizard_manual_namespace_test.go

@@ -0,0 +1,104 @@
+package ui
+
+import (
+	"errors"
+	"testing"
+
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func typeKeys(t *testing.T, m model, text string) {
+	t.Helper()
+	for _, r := range text {
+		m.handleAddWizardKeys(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{r}})
+	}
+}
+
+func TestNamespacesLoaded_ListFailureSwitchesToManualEntry(t *testing.T) {
+	m := newModelWithWizard(StepSelectNamespace)
+	m.ui.addWizard.loading = true
+
+	m.handleNamespacesLoaded(NamespacesLoadedMsg{err: errors.New("namespaces is forbidden")})
+
+	w := m.ui.addWizard
+	assert.True(t, w.namespaceManual)
+	assert.Equal(t, InputModeText, w.inputMode)
+	assert.NoError(t, w.error)
+	assert.False(t, w.loading)
+	assert.Contains(t, m.renderSelectNamespace(), "Enter Namespace")
+	assert.Contains(t, m.renderSelectNamespace(), "forbidden")
+}
+
+func TestNamespacesLoaded_EmptyListSwitchesToManualEntry(t *testing.T) {
+	m := newModelWithWizard(StepSelectNamespace)
+
+	m.handleNamespacesLoaded(NamespacesLoadedMsg{namespaces: []string{}})
+
+	assert.True(t, m.ui.addWizard.namespaceManual)
+}
+
+func TestNamespacesLoaded_ListedNamespacesKeepSelectionMode(t *testing.T) {
+	m := newModelWithWizard(StepSelectNamespace)
+
+	m.handleNamespacesLoaded(NamespacesLoadedMsg{namespaces: []string{"default", "kube-system"}})
+
+	w := m.ui.addWizard
+	assert.False(t, w.namespaceManual)
+	assert.Equal(t, InputModeList, w.inputMode)
+	assert.Equal(t, []string{"default", "kube-system"}, w.namespaces)
+}
+
+func TestManualNamespace_TypeAndConfirm(t *testing.T) {
+	m := newModelWithWizard(StepSelectNamespace)
+	m.handleNamespacesLoaded(NamespacesLoadedMsg{err: errors.New("forbidden")})
+
+	// k and j must be typed, not treated as navigation
+	typeKeys(t, m, "kube-jack")
+	assert.Equal(t, "kube-jack", m.ui.addWizard.textInput)
+
+	m.handleAddWizardEnter()
+
+	w := m.ui.addWizard
+	assert.Equal(t, "kube-jack", w.selectedNamespace)
+	assert.Equal(t, StepSelectResourceType, w.step)
+	assert.Equal(t, InputModeList, w.inputMode)
+	assert.Empty(t, w.textInput)
+}
+
+func TestManualNamespace_RejectsInvalidName(t *testing.T) {
+	m := newModelWithWizard(StepSelectNamespace)
+	m.handleNamespacesLoaded(NamespacesLoadedMsg{err: errors.New("forbidden")})
+	m.ui.addWizard.selectedNamespace = ""
+
+	for _, bad := range []string{"", "Has_Upper", "-leading", "trailing-"} {
+		m.ui.addWizard.textInput = bad
+		m.handleAddWizardEnter()
+
+		w := m.ui.addWizard
+		require.Error(t, w.error, "name %q", bad)
+		assert.Equal(t, StepSelectNamespace, w.step, "name %q", bad)
+		assert.Empty(t, w.selectedNamespace, "name %q", bad)
+	}
+}
+
+func TestManualNamespace_BackFromLaterStepRestoresTextInput(t *testing.T) {
+	m := newModelWithWizard(StepSelectResourceType)
+	m.ui.addWizard.namespaceManual = true
+
+	m.handleAddWizardKeys(tea.KeyMsg{Type: tea.KeyEsc})
+
+	w := m.ui.addWizard
+	assert.Equal(t, StepSelectNamespace, w.step)
+	assert.Equal(t, InputModeText, w.inputMode)
+}
+
+func TestKeysJK_StillNavigateInListMode(t *testing.T) {
+	m := newModelWithWizard(StepSelectResourceType)
+	m.ui.addWizard.inputMode = InputModeList
+
+	m.handleAddWizardKeys(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'j'}})
+
+	assert.Equal(t, 1, m.ui.addWizard.cursor)
+}