* fix(app): keep provider settings above model selector
Desktop web comboboxes used the browser top layer, so ordinary modal portals could not cover them. Keep web overlays in one relative layer stack while preserving native bottom-sheet stacking.
* fix(app): route overlay keyboard ownership
* fix(app): preserve nested overlay ownership
* fix(app): route command center overlay input
* fix(app): preserve global overlay ancestry
* fix(app): register global dialog hosts
Keep service route choices independent of daemon transport and persist the selected route per host. Use the shared web overlay stack so menus, tooltips, and toasts layer predictably.
Track proxy route changes from the Git branch rather than the workspace title to avoid transient service health changes.