docs: add JSDoc to WhereCell and improve Stripe plugin typings

[NitinSemwal2605]

docs: add JSDoc to WhereCell and improve Stripe plugin typings

Which branch should this PR target?

• main

What?

This PR resolves a couple of incomplete documentation and typing issues in the codebase marked with @todo / TODO.

1. packages/ui: Adds a comprehensive JSDoc block to transformWhereToNaturalLanguage and QueryPresetsWhereCell, replacing a vague /** @todo: improve this */.
2. packages/plugin-stripe: Improves typings and adds JSDoc to all exported types in types.ts. Specifically, it derives stripeResourceType directly from the Stripe SDK instead of a hardcoded union ('customers' | 'products'), and computes stripeResourceTypeSingular from the former so the two cannot go out of sync.

Why?

• Proper JSDoc improves the developer experience by surfacing parameter signatures, examples, and known limitations (such as transformWhereToNaturalLanguage currently only reading the first condition) in the IDE.
• Tying the Stripe resource types directly to the Stripe SDK (keyof Pick<Stripe, ...>) eliminates the need to manually update static union types if new resource types are supported in the future. Deriving the singular mapping via a utility type ensures the plural/singular counterparts never drift apart.

How?

In packages/ui/.../WhereCell/index.tsx:

• Replaced the single-line @todo with a full JSDoc block detailing the function's parameters, return values, an example, and a note about its current limitations.

In packages/plugin-stripe/src/types.ts:

• Added a StripeResourceSingularMap mapping plural keys to singular string literals.
• Updated stripeResourceType to keyof Pick<Stripe, 'customers' | 'products'>.
• Updated stripeResourceTypeSingular to look up the singular form from the map using stripeResourceType.
• Added JSDoc blocks explaining each property in SyncConfig, StripePluginConfig, and others.

Fixes #