Add dev guides

[tapios]

Purpose

Adds DeveloperGuides as a subtree, with a local agent file.

Only one file here needs review: the local AGENTS.md in the repo root. The rest is copied from the DeveloperGuides repo and needs to be changed there.

To-do

Content

---

• I have read and checked the items on the review checklist.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.02%. Comparing base (14ef3e6) to head (8ef4ce2).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #715   +/-   ##
=======================================
  Coverage   92.02%   92.02%           
=======================================
  Files          54       54           
  Lines        2321     2321           
=======================================
  Hits         2136     2136           
  Misses        185      185           

Components	Coverage Δ
src	92.99% <ø> (ø)
ext	69.47% <ø> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[trontrytel]

What is the process for updating the rules added here? Will we have to copy paste from DeveloperGuides repo every time? cc @imreddyTeja @dennisYatunin

[tapios]

What is the process for updating the rules added here? Will we have to copy paste from DeveloperGuides repo every time? cc @imreddyTeja @dennisYatunin

You can update DeveloperGuides. The subtrees in the repo are then updated by automated PRs (right now set to run monthly). The local AGENTS.md is updated locally.