Investigated the coding-matrix gap per Rene: vendor_compat is NOT derived
per-SKU from fx_compatibilities (found rows with vendor_compat fully populated
but fx_compatibilities empty, and vice versa -- zero correlation). It is a
shared OEM-coding-pattern reference template keyed by (speed_gbps,
form_factor): only 11 distinct templates exist across the whole Flexoptix
catalog, essentially 1:1 with family (one ambiguous exception, 100G/SFP,
deliberately excluded). Backfilled 2,587 rows from sibling templates (fill-only,
skips any family with 0 or >1 distinct templates). Flexoptix >=100G coding gap
dropped from 192 to 25 missing. New trigger (trg_fill_vendor_compat_from_family)
keeps this self-healing: every future Flexoptix product inherits its family
template automatically once speed_gbps+form_factor are known (after detail
sync), instead of needing another one-off backfill.
Deliberately NOT extended to competitor products in this pass -- needs a
separate, more careful evaluation of what this data actually represents for
non-Flexoptix parts before propagating via equivalence.
