Copilot review follow-ups:
- `applyProtocolVersion` took the value straight from an unvalidated JSON
body and went to `RegExp.test`, which coerces — `123` and `true` both
matched the token pattern and reached `Transport.setProtocolVersion` with
the wrong type. It now takes `unknown` and checks `typeof === "string"`
first, with cases for the coercible values.
- Replace `as unknown as Transport` in the new session fixtures with a
`makeTransport()` helper returning a structurally valid `Transport`, so an
interface change stays visible to the tests.
- Drop `as unknown as typeof fetch` in the new transport test —
`vi.fn<typeof fetch>()` is already the right type.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0119LaPQ3v4NyBK3ZTdM9j84
ddfce0f7ac