feat(catalog): add OAuth server setup flow - #113

Summary

• Add an OAuth-specific catalog setup dialog built from existing shadcn primitives.
• Register credentials, launch authorization, enable the server, then discover tools.
• Surface caller-scoped OAuth status and re-authorization actions on catalog cards.

Backend dependency

Requires backend PRs #6588 and #6620. Handwritten frontend contract types are temporary until OpenAPI generation includes the merged API.

Validation

• npm run lint -- --max-warnings=0
• npx tsc --noEmit
• npm run test -- --run src/pages/ServerCatalog.test.tsx src/components/server-catalog/CatalogResults.test.tsx src/api/catalog.test.ts

Screenshot