Each of the four oversized files (training/store.go 1569 LOC, ucca/rules.go 1231 LOC,
ucca_handlers.go 1135 LOC, document_export.go 1101 LOC) is split by logical group
into same-package files, all under the 500-line hard cap. Zero behavior changes,
no renamed exported symbols. Also fixed pre-existing hazard_library split (missing
functions and duplicate UUID keys from a prior session).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
9f96061631