Consolidate ask_user E2E snapshots into single canonical folder (#1311)

Three sibling folders existed for the same scenario in test/snapshots/:

- ask_user/ (canonical, targeted by all five SDK harnesses)

- ask-user/ (unused legacy duplicate)

- askuser/ (unused legacy duplicate)

All five SDK E2E harnesses (Node, Python, Go, .NET, Rust) resolve their

snapshot path to ask_user/. Removed the two duplicate folders and three

stale files inside ask_user/ that were left over from before the test

names were normalized to use a should_ prefix (PR #304). Only the three

canonical should_*.yaml files remain.

Fixes #314

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: stephentoub