test: cover has-many deleteAll bindings

[elpete]

Refs #124

Issue review

Fit score: 9/10. Relationship deleteAll() must bind the parent foreign-key value correctly. Substituting a boolean can delete the wrong rows or fail at the database boundary, so this behavior warrants a permanent integration regression.

Reasons for

• protects a destructive operation from incorrect bindings
• exercises the normal Quick relationship API and real database effects
• verifies unrelated parents are not affected

Reasons against

• the original report depended on older Quick/qb versions and specific entity metadata that is no longer available
• application-level cascades remain preferable when no per-child business logic is needed

Attempted reproduction

I reproduced the reported shape with a loaded User, its hasMany( Post ) relationship, and user.posts().deleteAll() on current next with qb 14.0.0-beta.3. The bug did not reproduce: only rows bound to user ID 1 were deleted, and another user’s posts remained. No production change was needed, so this PR adds the public-API regression that proves the current behavior.

Validation

• focused HasManySpec: 14 passed, 0 failed, 0 errors
• full suite: 496 passed, 0 failed, 0 errors, 3 skipped
• box run-script format
• git diff --check
• qb dependency: 14.0.0-beta.3