feat: config profiles top-level navigation with split-pane UI

- Move Config Profiles from settings to top-level navigation
- Implement split-pane layout: profile list on left, editor on right
- Add project and tool type dropdowns with live data
- Keep form open after save with success feedback
- Add sticky save bar at bottom of editor
- Remove Config Profiles tab from Settings page

OpenSpec: add-config-profiles

apps/web/src/pages/settings.tsx

@@ -9,7 +9,6 @@ type SettingsStatus = "loading" | "ready" | "error";
 const TABS = [
   { label: "General", path: "general" },
   { label: "SSH Keys", path: "ssh-keys" },
-  { label: "Config Profiles", path: "config-profiles" },
 ] as const;
 
 const THEME_OPTIONS = [