Teams page: offer both "New team" and "+ New team in <team>" when a team is selected

[santoshkumarradha]

Today the teams rail shows only + New team in <name> when a team is selected — the top-level + New team is only visible with no team selected. A selected team should offer both options: top-level + New team and nested + New team in <current team>.

Details

• internal/tui3/teamspagedraw.go: teamsRailNew / teamsRailNewWords currently draw only the nested variant when a team is selected; add the top-level option alongside it.
• internal/tui3/teamsacts.go: teamsActNewTeam with no id already creates a top-level team — wire the new row to it (nil id vs t.ID).
• Maintain the narrow-rail two-row presentation and nesting-limit dim/hint behavior for the nested option.