[client] Tag hidden windows with the popup that hid them

Windows hidden while a popup owned the screen went into one untagged list, so
whichever popup closed first restored all of them and emptied the list. An
install started during SSO login re-showed the main window the login popup had
deliberately hidden, and left the login popup with nothing to restore.

Each entry now records the popup that hid it, and a restore releases only that
popup's own entries. This also subsumes the manual filtering CloseRenewFlow did
to keep its own session-expiration window from being re-shown.

client/ui/services/windowmanager_test.go

@@ -0,0 +1,87 @@
+//go:build !android && !ios && !freebsd && !js
+
+package services
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func ownersOf(hidden []hiddenWindow) []string {
+	owners := make([]string, 0, len(hidden))
+	for _, h := range hidden {
+		owners = append(owners, h.owner)
+	}
+	return owners
+}
+
+func TestRestoreHiddenWindowsLockedOnlyReleasesItsOwn(t *testing.T) {
+	s := &WindowManager{
+		hiddenWindows: []hiddenWindow{
+			{owner: "browser-login"},
+			{owner: "install-progress"},
+			{owner: "browser-login"},
+		},
+	}
+
+	s.restoreHiddenWindowsLocked("install-progress")
+	assert.Equal(t, []string{"browser-login", "browser-login"}, ownersOf(s.hiddenWindows))
+
+	s.restoreHiddenWindowsLocked("browser-login")
+	assert.Empty(t, s.hiddenWindows)
+}
+
+func TestRestoreHiddenWindowsLockedUnknownOwnerKeepsEverything(t *testing.T) {
+	s := &WindowManager{
+		hiddenWindows: []hiddenWindow{{owner: "browser-login"}},
+	}
+
+	s.restoreHiddenWindowsLocked("welcome")
+	assert.Equal(t, []string{"browser-login"}, ownersOf(s.hiddenWindows))
+}
+
+func TestRestoreHiddenWindowsLockedEmptyIsNoop(t *testing.T) {
+	s := &WindowManager{}
+	require.NotPanics(t, func() { s.restoreHiddenWindowsLocked("browser-login") })
+	assert.Empty(t, s.hiddenWindows)
+}
+
+func TestStampGenerationTracksLatestPerWindow(t *testing.T) {
+	s := &WindowManager{generation: map[string]uint64{}}
+
+	first := s.stampGeneration("browser-login", "/#/dialog/browser-login")
+	assert.Equal(t, "/#/dialog/browser-login?gen=1", first)
+	assert.True(t, s.matchesGeneration("browser-login", 1))
+
+	second := s.stampGeneration("browser-login", "/#/dialog/browser-login?uri=x")
+	assert.Equal(t, "/#/dialog/browser-login?uri=x&gen=2", second)
+	assert.False(t, s.matchesGeneration("browser-login", 1))
+	assert.True(t, s.matchesGeneration("browser-login", 2))
+}
+
+func TestMatchesGenerationUntrackedWindowAccepts(t *testing.T) {
+	s := &WindowManager{generation: map[string]uint64{}}
+	assert.True(t, s.matchesGeneration("main", 0))
+}
+
+func TestPaintedGeneration(t *testing.T) {
+	tests := []struct {
+		name string
+		data any
+		want uint64
+	}{
+		{"string", "7", 7},
+		{"float", float64(7), 7},
+		{"slice", []any{"7"}, 7},
+		{"empty slice", []any{}, 0},
+		{"unparsable", "abc", 0},
+		{"nil", nil, 0},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.want, paintedGeneration(tc.data))
+		})
+	}
+}