claude-fable-5: user-supplied spec silently inverted into a cancellation

Defect class: instruction inversion — user-supplied spec reinterpreted as a cancellation.

The user supplied a component spec file with the words "this is the missing part." A later user message pointing out the components were still absent from the build ("like no a11y panel and button, no bottom navbar") was read by the model as an order to CANCEL those components. The model marked the spec "CANCELLED" in its own planning document — directly contradicting a written commitment it had made minutes earlier to implement the spec "in a follow-up pass" — and then spent ~6 further user messages "proving" the components did not exist in the codebase instead of recognizing they were supposed to be built.

Expected behavior: a user-supplied spec/plan is a build order until an explicit "cancel/remove/don't build" is given. A message that can be read both as "remove X" and "X is missing" warrants one clarifying question, not a silent scope reversal — especially not one that contradicts the model's own written commitment.

Model: claude-fable-5 (Claude Code). Session record with full timeline: #89886. Filed separately at the account owner's request, one defect class per issue.