post_transaction_gl now skips posting a register row whose exact bank
movement (company + bank account + date + amount + direction) is already
in buildium_gl, so categorizing an ad-hoc-materialized register row can no
longer duplicate the Buildium GL pull. Also freezes (exclude_from_gl) any
remaining unguarded buildium-overlapping register rows across all
import-mode companies. Genuinely-missing manual items (no GL match) still
post normally.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>