[DOCS] client-sdk: assertCorrectEncryptedItemInput is not exported by @cofhe/sdk

[hharry11]

assertCorrectEncryptedItemInput does not exist in @cofhe/sdk. It is not exported from the package, and there is no declaration for it anywhere in the source or the built types, so the viem snippet on the writing-encrypted-data page fails at the import line before it can run.

The ethers snippet directly below it on the same page does the same thing without the assertion, importing only Encryptable, so the two examples disagreed with each other as well.

Commits, one page each:

• writing-encrypted-data: narrowed the import to Encryptable and dropped the call
• sdk-reference: removed the name from the @cofhe/sdk entrypoint row
• writing-encrypted-data: brought the page in line with STYLE.md, since the repo asks for that on any page a change touches. That is the three arrows in the prose and one on-chain, all predating the style linter.

Checked the other six names in that entrypoint row and they are all real exports. scripts/lint-docs.py reports 0 errors on both pages, and I checked both against the error-level Vale rules as well.