fix: regenerate pnpm-lock.yaml with pnpm v8 (lockfileVersion 6.0)

The CI workflows pin pnpm/action-setup@v5 with version: 8, which uses
lockfile format v6.0. The previous regen used pnpm 10 producing v9.0,
which pnpm 8 in CI couldn't read cleanly — pnpm install would rewrite
the lockfile, leaving the working tree dirty and breaking
'pnpm version patch' in the publish workflow.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JohnMcLear