feat(settings): drive providers panel from pi-mono catalog

ProvidersPanel reads all 26 CONNECTOR_CATALOG entries and groups them by
auth kind (OAuth / API key / Azure / AWS / Vertex). ProviderRow
dispatches to the matching dedicated form component per auth kind. AWS,
Azure, Vertex forms rewritten with Tailwind classes and a shared field
style module so the Settings pane renders with the same aesthetic as the
rest of the app.

src/renderer/components/settings/providers/index.ts

@@ -0,0 +1,2 @@
+export { ProvidersPanel } from "./ProvidersPanel";
+export { ProviderRow } from "./ProviderRow";