sql/119: product_type enum (module|dac|aoc|aec|switch|nic|accessory) computed by
trigger trg_transceivers_biu from part_number/category/reach on every insert/update.
Backfilled 41008 rows (36284 module, 2791 dac, 1835 aoc, 29 aec, 27 accessory,
26 switch, 16 nic). Cables and switches/NICs no longer counted as modules;
BASE-T/RJ45 copper modules protected from cable demotion; AOC/DAC keyword beats
the optical-token guard. Consumers filter product_type=module.
sql/120: conservative form_factor recovery. Corrects only provably-wrong rows
(form_factors.max_speed < speed_gbps) via an explicit title token; 87 fixed
(e.g. 400G cables mislabelled SFP+ to QSFP-DD), 947 opaque rows left untouched
(never guessed). Scraped original preserved in new column form_factor_raw.
sql/121: document lead_time_days as not-collected (0 percent populated on all
time-series tables) so no consumer fabricates a default.
scraper/utils/db.ts: note that product_type/form_factor are trigger-maintained.
