Patch Minor Dependencies, Review Major Upgrades

Update third-party dependencies to their latest compatible versions. Apply patch and minor updates, run the test suite, and fix any breakage. List major-version upgrades that need review in the pull request description instead of applying them.

Every third-party dependency was already at its latest version: no npm deps; the GitHub Actions match their latest tags and SHAs; serve is unpinned. Gate green, no PR. Deferred major for review: Node 20 (EOL) → 22/24 in CI and deploy. Details in the report.