mod/trace-rules evaluates a report against every rule, returning each rule's
proved/unproved status + goal-by-goal derivation (an unproved rule shows which
goal failed). mod/first-proved = winner (matches engine precedence, cross-checked),
mod/proved-rules the firing set, mod/trace-report a [fires]/[ - ] rendering.
Answers 'why didn't my rule fire?' without instrumenting the engine. +15 tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
