refactor(board): make recursive copy fallback explicit

[jonathanwxh-cell]

Fixes #2362.

Recursive board copying currently relies on the misspelled err.respose condition to fall back to a cached child board on API errors. Remove that condition in both current-master implementations and make the existing fallback explicit. Correcting only the spelling would instead stop copying cached children on 401/500 responses.

Add shared, parameterized tests that exercise both container methods: network/404/401/500 failures still copy the local child and retarget the parent's link; a successful fetch uses the remote child; an unavailable child without a cached copy does not prevent copying a later sibling. Export the Communicator container by name so the same tests exercise it directly.

Validation on Node 22.23.2:

• All 12 new cases pass against the original fallback logic.
• A temporary spelling-only change produces four expected failures (401/500 in both implementations). That change was removed.
• Final focused run: 3 suites and 17 tests pass, including both existing container test files.
• Changed-file Prettier checks, git diff --check, and the commit hook pass.
• CircleCI on commit 80efe63: all 63 selected suites, 446 tests, and 65 snapshots pass. Repository-wide formatting, Codacy, and Snyk checks also pass.

The tests use mocked API responses and local/guest copy state; no browser/backend end-to-end run was performed for this behavior-preserving cleanup.

This PR targets current master. #2293 moves the Communicator implementation into hooks/useBoardCrud.js, so the same cleanup will need to be carried over if that refactor lands first. I asked about ownership and the preferred target branch in #2362 before preparing this change.