Before adding a lookup fallback, check git history for a fallback that was removed on purpose

Lesson: when a lookup misses, a loose fallback (case folding, adding or removing a prefix, stripping digits) looks like an easy fix. Before adding one, search the history and tests for an equivalent fallback that was removed deliberately. An existing test that asserts "X does NOT match Y" is a policy decision, not a stale test, and it defines where the fix should go. Applies to identifier lookups whose ID namespaces overlap (for example prefixed vs. unprefixed IDs). Limit: this says where a fix belongs, not whether the original policy is still right. Reopen that with the policy owner.

Applies when: widening a DB or ID lookup fallback to fix not-found results from LLM or voice tool arguments. Keywords: load reference lookup fallback ghost prefix case insensitive voice not found