[Renovate Centralization] Phase 1: Define preset shape (base / frontend / backend split) #546

Context

Part of the Phase 1 discovery for epic #541 — Centralize Renovate config for openedx repos.

Task

Decide the shape of the shared presets:

• Option A: A single default preset that all repos extend
• Option B: A base preset + frontend and backend variants, given the known divergence between FE/BE repos

Background

Two distinct patterns exist today:

• Frontend (~42 repos): config:base, automerge @edx/@openedx minor+patch, rebaseStalePrs, often semanticCommits, weekly schedule
• Backend (~11 repos): config:base, broader automerge (minor, patch, pin, digest), prConcurrentLimit, weekday schedule

Questions to answer

• Is the FE/BE divergence significant enough to warrant separate presets?
• If split, what goes in base vs frontend vs backend?
• Can a single preset with packageRules handle both, or would it be too complex?

Output

A documented decision on preset structure with a draft of what goes in each preset.

References

• Parent epic: Centralize Renovate config for openedx repos (frontend + backend) #541
• Renovate preset docs: https://docs.renovatebot.com/config-presets/