feat(06-04): road-graph build tool — Overpass extract → pinned CSR binary with the D-01 stats gate
- maintainer-time repo tool (nothing in bot/web/routing src imports it): drivable-class
Overpass extract (Pitfall 1 filter), nodes deduped by rounded coord, oneway/-1/roundabout
flag law, maxspeed-tag overrides over class defaults, name-pool interning
- bbox derived mechanically from the committed corpus (gazetteer entries + golden pairs
± 0.05 deg, printed) — Open Q 4's pinning
- collect-then-write + ENFORCED size gate (>1 MB, <=80 MB, exit 1 outside) + advisory
30-80 MB band warning; --check mode decodes and re-prints the gate, zero network
- routing/data/.gitignore: *.bin is an ODbL-derived build artifact — forks build their own
- real KL graph built: 277514 nodes / 598396 edges / 21447 names / 13.1 MB (gate PASS,
band warning printed for review)