- trg_compat_speed_guard: BEFORE INSERT/UPDATE on compatibility forces
algorithmic (spec_match/community) rows whose transceiver is faster than the
switch max port speed to status=incompatible. Curated rows never touched.
Makes the "no physically-impossible compatibility" invariant structural, so
it survives a scraper regression.
- check_switch_quality(): on-demand proof; CI gate is
`select bool_and(pass) from check_switch_quality() where enforced` (must be
true). Data-source gaps (coding coverage, speed<=0, datasheet) tracked as
enforced=false so they do not fail the gate before the data exists.
