SCANNER_PROBE_RE Block M/N fleet parity

Gap surfaced by coder-mars-cc 2026-07-17 during Block O sync: Mars's SCANNER_PROBE_RE stops at Block L (nodesync) and is MISSING pluto-canonical Block M (backup-archive ext family) + Block N (compiled-asset sourcemap /*.js.map). Mars is thus less protected vs backup-archive + sourcemap enumeration probes than pluto. Close the parity gap: mars pulls Block M+N from pluto canonical (byte-identical), re-proves 0-collision vs its own route manifest+assets, adopts. Venus CONFIRM its current M/N status first, adopt if missing. Pluto=canonical source (holds M/N). Same adopt pattern as Block O. Security hardening, probe-detection coverage (not an active vuln).