Restrict package-script trimming to ASCII whitespace

[hzw0813]

Summary

• replace JavaScript String.trim() in Node and Jest/Vitest package-script recognition with ASCII space/tab-only edge trimming
• keep ordinary shell-significant space/tab padding supported
• fail closed on leading or trailing non-ASCII whitespace such as NBSP instead of silently erasing it into a different recognized command
• add Node and Jest regressions for both accepted ASCII padding and rejected Unicode edge whitespace
• regenerate tracked dist and document the boundary in the changelog

Why

The parsers already normalized only [ \t]+ internally after the multiline hardening, but both still called String.trim() first. JavaScript trim() removes a wider Unicode whitespace set, including NBSP. A package script such as node --test\u00a0 or \u00a0jest --ci could therefore be normalized by ProofDiff into a supported exact-target command even though that non-ASCII character is not ordinary shell separator whitespace. That creates a semantic mismatch between the repository script and the targeted command ProofDiff actually runs.

The fix narrows edge trimming to exactly spaces and tabs, matching the parser's existing internal normalization boundary.

Verification

• full npm test passed after the change
• clean npm run clean && npm run build passed
• final branch diff contains only source, tests, changelog, and regenerated dist; temporary updater files were removed