chore(scripts): delete the four root scripts held back from the first cleanup PR

measure-markdown-ts-blocks.mjs and measure-reserved-identity-name-census.mjs
are named only by shipped CHANGELOG entries; pm/measurement-claim-triage.mjs
only by one historical census row in a dispatch-gates.mjs docblock, which now
names commit 7111e14 as the one holding it; bench/runtime-publish-gate.bench.mts
only by a path string dispatch-gates.self-test.mjs hands to a pure predicate.

Claude-Session: https://claude.ai/code/session_01LbdJFR3AmcKLZKQafYE1tN
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude