Initial environment checks: Node v22.16.0; Python 3.13.5.
Attempted OS network namespace: `unshare -n true`.
Result: unshare: unshare failed: Operation not permitted (exit 1).
This is an unavailable isolation capability, not an input-verification failure.
A separate Node preload guard blocks network modules/fetch and child-process imports.
The supplied sources remain unmodified. No actual network operation is requested.
The receiver has been inspected before execution. Its global-colours module contains
an unused online-fetch function; the offline validation path does not call it.
