* Add unit tests for ChatViewModel attachment manipulation
Adds tests covering addAttachment, removeAttachment (valid/invalid indices),
and clearAttachments in ChatViewModelTest. This ensures the attachment
state management logic works as expected.
* test(#511): add mixed valid/invalid remove sequence + DRY attachment setup
Folds in both Sourcery review notes:
- New testRemoveAttachment_mixedValidAndInvalidSequence asserts list
stays consistent across a valid remove, out-of-bounds + negative no-ops,
then another valid remove on the shifted list.
- addDummyAttachments() helper removes repeated VM/advance/add boilerplate.
Verified: ktlintCheck clean + ChatViewModelTest 37/37 pass locally.
M57
529ab0bc83