Scans CLAUDE.md and PRD.md for verifiable code references — backtick
file paths, API route patterns (METHOD /api/...), and bare *.jsx
component names — then cross-checks each against the filesystem and
server/src/routes/ source tree.
Prints a per-reference PASS/FAIL table with source doc and line number.
Exits non-zero on any drift so it can gate CI.
Run with: node scripts/doc-drift.js
Nightshift-Task: doc-drift
Nightshift-Ref: https://github.com/marcus/nightshift