fix: pagination returning duplicate results when timestamps: false (#13920)

### What
Fixes a bug where collection docs paginate incorrectly when `timestamps:
false` is set — the same docs were appearing across multiple pages.

### Why
The `find` query sanitizes the `sort` parameter.  

- With `timestamps: true`, it defaults to `createdAt`
- With `timestamps: false`, it falls back to `_id`

That logic is correct, but in `find.ts` we always passed `timestamps:
true`, ignoring the collection config. With the right sort applied,
pagination works as expected.

### How
`find.ts` now passes `collectionConfig.timestamps` to
`buildSortParam()`, ensuring the correct sort field is chosen.

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Fixes #13888