natmap consumes the shared inspect API

[FAZuH]

34 — natmap consumes the shared inspect API

What to build: natmap drops its local get_port_mappings parsing and reads the shared lab-lib inspection shape for its mapping flow. Behavior is unchanged; the format is defined once in lab-lib.

Blocked by: #33 — the shared inspection module must land first.

Status: ready-for-agent

• natmap's mapping flow uses the lab-lib inspect API; no local inspect-parse duplication remains
• Port-mapping tests re-point at the shared shape; behavior unchanged
• natmap lib suite green