Show a colour-coded team picker instead of cycling with T

T used to silently cycle Model.activeTeamID through the caller's teams with
no visible list of choices. It now opens a full picker (modelled on the
existing user picker) listing every team plus "All teams", each with a
stable identity colour from a new six-colour theme palette. The same colour
now also shows as a bullet next to "team: <name>" in the header, so the
active team stays visible without opening the picker.

Adds an Identity palette to the theme package (six hues, skipping the ones
that already mean firing/critical), Styles.TeamColor to pick one by team id,
and identity_1..6 as theme-file tokens alongside the existing twelve so a
fully custom theme can still set every token.

internal/tui/update_test.go

@@ -630,7 +630,7 @@ func TestAlertDetail_JumpToIncident(t *testing.T) {
 
 // A refresh underneath a prompt would move the ground under the user.
 func TestRefreshTick_SkipsModalStates(t *testing.T) {
-	modal := []mode{modeNote, modeSnooze, modeConfirm, modeUserPicker, modeUserCreate}
+	modal := []mode{modeNote, modeSnooze, modeConfirm, modeUserPicker, modeTeamPicker, modeUserCreate}
 	for _, md := range modal {
 		m := sized()
 		m.mode = md
@@ -782,32 +782,38 @@ func TestConnected_DefaultTeamFromConfig(t *testing.T) {
 	}
 }
 
-func TestSwitchTeam_CyclesAllThenEachTeam(t *testing.T) {
+func TestTeamPicker_Opens(t *testing.T) {
 	m := sized()
 	m.teams = twoTeams()
-	var seen []int64
-	for i := 0; i < 4; i++ {
-		var cmd tea.Cmd
-		m, cmd = press(t, m, "T")
-		if cmd == nil {
-			t.Fatal("switching team should reload")
-		}
-		seen = append(seen, m.activeTeamID)
+	m, cmd := press(t, m, "T")
+	if m.mode != modeTeamPicker {
+		t.Fatalf("T should open the team picker, got mode %v", m.mode)
 	}
-	want := []int64{1, 2, 0, 1}
-	for i := range want {
-		if seen[i] != want[i] {
-			t.Fatalf("expected the cycle %v, got %v", want, seen)
-		}
+	if cmd != nil {
+		t.Error("opening the picker should not itself trigger a reload")
 	}
 }
 
-func TestSwitchTeam_ClearsRowsFromTheOtherTeam(t *testing.T) {
+// Row 0 of the picker table is always "All teams"; row i (i>=1) is
+// m.teams[i-1] — see rebuildTeamPickerTable.
+func TestTeamPicker_SelectTeamClearsRowsFromTheOtherTeam(t *testing.T) {
 	m := sized()
 	m.teams = twoTeams()
 	m.incidents = []api.Incident{{ID: 1, Title: "old", TeamName: "Ops"}}
 	m.rebuildIncidentTable()
+
 	m, _ = press(t, m, "T")
+	m.teamPickerTable.SetCursor(1) // twoTeams()[0] is Ops
+	m, cmd := press(t, m, "enter")
+	if cmd == nil {
+		t.Fatal("selecting a team should reload")
+	}
+	if m.mode != modeDashboard {
+		t.Fatalf("enter should close the picker, got mode %v", m.mode)
+	}
+	if m.activeTeamID != 1 {
+		t.Fatalf("expected team 1 (Ops) active, got %d", m.activeTeamID)
+	}
 	if len(m.incidents) != 0 {
 		t.Errorf("the previous team's incidents must not linger, got %d", len(m.incidents))
 	}
@@ -816,10 +822,44 @@ func TestSwitchTeam_ClearsRowsFromTheOtherTeam(t *testing.T) {
 	}
 }
 
-func TestSwitchTeam_NoTeamsDoesNothing(t *testing.T) {
+func TestTeamPicker_SelectAllTeams(t *testing.T) {
+	m := sized()
+	m.teams = twoTeams()
+	m.activeTeamID = 1
+
+	m, _ = press(t, m, "T")
+	m.teamPickerTable.SetCursor(0) // "All teams"
+	m, cmd := press(t, m, "enter")
+	if cmd == nil {
+		t.Fatal("selecting all teams should reload")
+	}
+	if m.activeTeamID != 0 {
+		t.Fatalf("expected all teams (0), got %d", m.activeTeamID)
+	}
+}
+
+func TestTeamPicker_EscCancelsWithoutChangingTeam(t *testing.T) {
+	m := sized()
+	m.teams = twoTeams()
+	m.activeTeamID = 1
+
+	m, _ = press(t, m, "T")
+	m, cmd := press(t, m, "esc")
+	if cmd != nil {
+		t.Error("cancelling should not reload")
+	}
+	if m.mode != modeDashboard {
+		t.Fatalf("esc should close the picker, got mode %v", m.mode)
+	}
+	if m.activeTeamID != 1 {
+		t.Fatalf("cancelling must not change the active team, got %d", m.activeTeamID)
+	}
+}
+
+func TestTeamPicker_NoTeamsDoesNothing(t *testing.T) {
 	m, cmd := press(t, sized(), "T")
-	if cmd != nil || m.activeTeamID != 0 {
-		t.Errorf("without teams T has nothing to switch to")
+	if cmd != nil || m.mode == modeTeamPicker {
+		t.Errorf("without teams T has nothing to open")
 	}
 }