test(assets): add unit tests for transfer subcommand

[iborazzi]

Description

Adds unit test coverage for assetsCommand's transfer subcommand in src/commands/assets.ts, which previously had no tests.

Details

• Tests that the command registers the transfer subcommand correctly.
• Tests that a valid --body JSON file is read and POSTed to /api/v2/assets/transfer.
• Tests error handling when the --body file does not exist.
• Tests error handling when the --body file contains invalid JSON.

All 362 tests pass locally (npx vitest run), including the 4 new tests.

[ryanio]

Thanks for this. assetsCommand really was the last command module in the CLI with no test file, and covering both readJsonBodyOption failure paths while asserting that no request goes out was the right shape for it.

Recreated in our internal monorepo and shipped in @opensea/cli v2.2.0, with you credited as co-author. This repo is a read-only mirror so we cannot merge PRs here. Closing as shipped.