fix: Reset all clears the Kanban project binding

[paolino]

Summary

• `clearAll` now also removes `gh-dashboard-kanban-project` and `gh-dashboard-agent-server` from localStorage, and `ResetAll` resets the corresponding state fields. Previously, Reset All left the project binding in place, so pasting a new token landed on an empty Kanban with no way to change it.
• Settings shows the current Kanban project (by title) with a Change project button that clears the binding and re-fetches the project list — no DevTools needed.
• `Initialize` / `SubmitToken` / `SwitchPage` auto-fetch the project list when no project is selected, so the setup picker appears without a manual refresh.

Test plan

• With a project selected, open Settings — project title is shown.
• Click Change project — picker appears, items stop rendering, localStorage key `gh-dashboard-kanban-project` is removed.
• Reset all → re-enter token → Kanban setup picker appears with the project list populated.
• Paste a token whose account has no project yet — picker shows "No projects found" plus the Create Kanban project button.