fix: Rewrite direct s3 urls to point to assets.pubpub.org

[isTravis]

Some asset URLs in the database use the raw S3 endpoint (https://s3.amazonaws.com/…) instead of the CDN-friendly https://assets.pubpub.org/… form. These bypass our cache, resulting in slower loads and unnecessary S3 egress.

This adds tools/rewriteS3Urls.ts which scans every column known to store asset URLs and rewrites the S3 prefixes in place.

What it rewrites

From	To
https://s3.amazonaws.com/assets.pubpub.org/…	https://assets.pubpub.org/…
https://s3-external-1.amazonaws.com/assets.pubpub.org/…	https://assets.pubpub.org/…

Columns covered

• TEXT columns: avatars, logos, images across Communities, Pubs, Pages, Collections, Users, Attributions, ExternalPublications, Exports, PubHeaderTheme
• Freetext/HTML columns: htmlTitle, htmlDescription, heroText, CustomScripts.content
• JSONB columns: Docs.content, Pubs.downloads, Pages.layout, Collections.layout, ThreadComments.content, Releases.noteContent, ReviewNews.reviewContent, Submissions.abstract, SubmissionWorkflows.*Text, DraftCheckpoints.doc, LandingPageFeatures.payload, ActivityItems.payload, WorkerTasks.input/output

Usage

pnpm run tools rewriteS3Urls            # dry-run — reports counts, changes nothing
pnpm run tools rewriteS3Urls --execute  # rewrites URLs