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/components/app-shell.tsx

@@ -15,6 +15,7 @@ const NAV_ITEMS: { to: string; label: string; icon: IconName; badge?: "sessions"
   { to: "/sessions", label: "Sessions", icon: "terminal", badge: "sessions" },
   { to: "/projects", label: "Projects", icon: "projects" },
   { to: "/tool-workshop", label: "Tool Workshop", icon: "settings" },
+  { to: "/config-profiles", label: "Config Profiles", icon: "folder" },
   { to: "/settings", label: "Settings", icon: "settings" }
 ];