refactor: remove JSON database backend and update db dump workflow

[adibarra]

Note

High Risk
Large architectural change: local dev and all read paths now require DATABASE_READONLY_URL, and the backup/restore format changed from JSON tar parts to pg_dump/pg_restore.

Overview
Removes the JSON dump / DUMP_DIR dev path so the app and API routes always read through PostgreSQL (getDb()). That drops JSON_MODE, the in-memory json-provider, admin:db:dump / admin:db:load-dump, and the related tests and TABLE_INSERT_ORDER helper.

API and caching are simplified: routes no longer branch to json-provider; cachedQuery no longer bypasses cache in dump mode. E2E fixtures (FIXTURES_MODE) are unchanged.

Docs and env now describe only live Postgres (standard TCP or Neon); README setup no longer mentions downloading JSON dumps for local dev.

Weekly DB backup no longer uses Node/pnpm dump scripts. It runs pg_dump (custom format) from a pinned Postgres 18 Docker image against DATABASE_WRITE_URL, excludes user_feedback data, xz-compresses and splits parts, and documents pg_restore in release notes.

^{Reviewed by Cursor Bugbot for commit a21fd44. Bugbot is set up for automated code reviews on this repo. Configure here.}

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
inferencemax-app	Ready	Preview, Comment	Jul 11, 2026 7:17pm

[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 7dce630. Configure here.}