fix: certify CJS measurement lifecycle

[clfhhc]

Complete the standalone integration package acceptance boundary.

• consume the cache-safe, cross-subpath-compatible @graphrefly/ts@0.6.4 floor
• use the generic MeasurementAdapter/textMeasurementProvider seam directly
• typecheck tests and remove the accidental Node 24 engine floor
• prove packed ESM and CJS consumers both with and without the optional canvas peer
• prove failed measurement deactivation is bounded and successful fake-canvas glyph-width measurement reaches exact outputs

Local proof: lint, typecheck, 2 tests, ESM/CJS/DTS build, npm pack, four runtime branches, and external-CWD consumers passed.