refactor(basics/close-account): replace borsh with kit codecs in native example

[amilz]

Summary

• basics/close-account/native was the last package pinned to borsh: ^0.7.0 — the only pre-2.x pin in the repo — and called deserialize(schema, Class, buffer), a signature that no longer exists in borsh 2.x. Dropped the dep and regenerated the lockfile.
• Instruction data now uses getStructEncoder, with addEncoderSizePrefix(getUtf8Encoder(), getU32Encoder()) for the name string, matching the pattern from refactor(tokens): use kit codecs for instruction data in Token-2022 and create-token examples #676.
• ts/state/index.ts exposes a userDecoder for the on-chain User layout in place of the borsh class boilerplate.
• Test asserts real post-state: the decoded account name after create, and the System Program owner plus zero-length data after close.

Test Plan

• pnpm build-and-test in basics/close-account/native — 3 passing
• pnpm exec tsc --noEmit -p tsconfig.json — clean
• pnpm run check (prettier) — clean
• Broke each new assertion once to confirm it fails loudly

Closes DEV-838

[linear]

DEV-838

[greptile-apps]

Greptile Summary

The PR replaces the native close-account example’s legacy TypeScript Borsh dependency with equivalent Solana Kit codecs and strengthens its integration assertions.

• Encodes create and close instructions with explicit Kit struct encoders matching the native Rust Borsh wire format.
• Exposes a Kit decoder for the on-chain User account layout.
• Verifies decoded state after creation and zero-length, System Program-owned state after closure.
• Removes Borsh and its transitive packages from the package manifest and lockfile.

Confidence Score: 5/5

The PR appears safe to merge, with the new codecs preserving the program’s existing wire and account-data layouts.

The create and close encoders match the Rust program’s Borsh discriminants and string representation, the decoder matches the persisted User layout, and the new post-state assertions reflect the program’s actual close behavior.

Important Files Changed

Filename	Overview
basics/close-account/native/ts/instructions/create.ts	Replaces Borsh serialization with an equivalent u8 discriminant and little-endian u32-prefixed UTF-8 name encoder.
basics/close-account/native/ts/instructions/close.ts	Replaces the single-byte Borsh close instruction with an equivalent Kit struct encoder.
basics/close-account/native/ts/state/index.ts	Replaces the unused Borsh model boilerplate with a decoder matching the program’s Borsh-serialized string field.
basics/close-account/native/tests/close-account.test.ts	Adds valid assertions for created account data and the program’s resize-to-zero and System Program reassignment close behavior.
basics/close-account/native/package.json	Removes the now-unused direct Borsh dependency while retaining all dependencies required by the new codecs.
basics/close-account/native/pnpm-lock.yaml	Regenerates the lockfile to remove Borsh and its no-longer-needed transitive dependencies.

_{Reviews (1): Last reviewed commit: "refactor(basics/close-account): replace ..." | Re-trigger Greptile}

[dev-jodee]

Refactor borsh→kit codecs in close-account. All CI green.