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.go

@@ -34,6 +34,7 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.rebuildArchivedTable()
 		m.rebuildScheduleTable()
 		m.rebuildUserPickerTable()
+		m.rebuildTeamPickerTable()
 		m.rebuildUserManageTable()
 		m.detailViewport.Width = m.width
 		m.detailViewport.Height = m.detailViewportHeight()
@@ -400,6 +401,12 @@ func (m Model) routeKey(msg tea.KeyMsg) (Model, tea.Cmd) {
 		m2, ourCmd := m.handleKey(msg)
 		return m2, tea.Batch(tableCmd, ourCmd)
 
+	case modeTeamPicker:
+		var tableCmd tea.Cmd
+		m.teamPickerTable, tableCmd = m.teamPickerTable.Update(msg)
+		m2, ourCmd := m.handleKey(msg)
+		return m2, tea.Batch(tableCmd, ourCmd)
+
 	case modeUserCreate:
 		var inputCmd tea.Cmd
 		m.userFormInputs[m.userFormFocus], inputCmd = m.userFormInputs[m.userFormFocus].Update(msg)
@@ -496,6 +503,8 @@ func (m Model) handleKey(msg tea.KeyMsg) (Model, tea.Cmd) {
 		return m.handleConfirmKey(msg)
 	case modeUserPicker:
 		return m.handleUserPickerKey(msg)
+	case modeTeamPicker:
+		return m.handleTeamPickerKey(msg)
 	case modeUserCreate:
 		return m.handleUserCreateKey(msg)
 	case modeUserNotifyEdit:
@@ -566,7 +575,7 @@ func (m Model) handleDashboardKey(msg tea.KeyMsg) (Model, tea.Cmd) {
 		if !m.connected || len(m.teams) == 0 {
 			return m, nil
 		}
-		return m.switchTeam()
+		return m.openTeamPicker()
 
 	case "enter":
 		switch m.activeSection {
@@ -847,22 +856,21 @@ func (m Model) openUserPicker(target pickerTarget) (Model, tea.Cmd) {
 	return m, nil
 }
 
-// switchTeam steps the active team through all teams, then each of the caller's
-// teams in turn, and reloads what depends on it. Sections that are not on screen
-// are emptied rather than fetched, so they load when next opened; the incident
-// queue is the exception because it is what the caller returns to.
-func (m Model) switchTeam() (Model, tea.Cmd) {
-	next := int64(0)
-	if m.activeTeamID == 0 {
-		next = m.teams[0].ID
-	} else {
-		for i, t := range m.teams {
-			if t.ID == m.activeTeamID && i+1 < len(m.teams) {
-				next = m.teams[i+1].ID
-			}
-		}
-	}
-	m.activeTeamID = next
+// openTeamPicker opens the full list of the caller's teams, plus "All teams",
+// for the "T" key to choose among rather than blindly cycling through them.
+// Team data is already loaded at connect time, so no fetch is needed.
+func (m Model) openTeamPicker() (Model, tea.Cmd) {
+	m.mode = modeTeamPicker
+	m.rebuildTeamPickerTable()
+	return m, nil
+}
+
+// selectTeam sets the active team to teamID (0 meaning all teams) and reloads
+// what depends on it. Sections that are not on screen are emptied rather than
+// fetched, so they load when next opened; the incident queue is the exception
+// because it is what the caller returns to.
+func (m Model) selectTeam(teamID int64) (Model, tea.Cmd) {
+	m.activeTeamID = teamID
 
 	m.incidents, m.alerts, m.archivedIncidents = nil, nil, nil
 	m.scheduleEntries, m.scheduleDays, m.currentOnCall = nil, nil, nil
@@ -1253,6 +1261,34 @@ func (m Model) handleUserPickerKey(msg tea.KeyMsg) (Model, tea.Cmd) {
 	return m, nil
 }
 
+// ── Team picker ───────────────────────────────────────────────────────────
+
+// handleTeamPickerKey reads the cursor's team off the table built by
+// rebuildTeamPickerTable, where row 0 is always "All teams" and row i (i>=1)
+// is m.teams[i-1].
+func (m Model) handleTeamPickerKey(msg tea.KeyMsg) (Model, tea.Cmd) {
+	switch msg.String() {
+	case "esc":
+		m.mode = modeDashboard
+		return m, nil
+
+	case "enter":
+		cursor := m.teamPickerTable.Cursor()
+		id := int64(0)
+		if cursor > 0 {
+			i := cursor - 1
+			if i < 0 || i >= len(m.teams) {
+				return m, nil
+			}
+			id = m.teams[i].ID
+		}
+		m, cmd := m.selectTeam(id)
+		m.mode = modeDashboard
+		return m, cmd
+	}
+	return m, nil
+}
+
 // scheduleConflicts reports which of dates are already held by somebody other
 // than newUserID, and the distinct names holding them.
 //