docs(specs): address greptile findings on #628

- M181 Invariant 5: pre-swap probes re-run the R-row parity oracles, not
  only the generic S-row gates (P1)
- M181 R1: route-parity command is executable verbatim via the locked
  --served argument (P1)
- M180: depends on M179_001 — shared seams settle before ingress (P2)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>