MidnightDKP 0.9.216 - Dashboard Default On Open

Base: 0.9.215.

- Standard Toggle opening always selects and displays Tableau de bord.
- Navigation highlight is refreshed through ShowPage("dashboard").
- EnsureMainWindowVisible() defaults to Tableau de bord when no page is supplied.
- Explicit OpenPage("admin"/"loot"/etc.) behavior is preserved.
- No visual, portrait, DKP, loot, sync, session or admin logic changes.
