docs: #ORGA-652 ajoute le CLAUDE.md du bundle presences

[damienromito]

Décrit l'architecture multi-modules (Maven, fronts AngularJS), les commandes réelles de build et de dev, et les garde-fous pour la refonte React de la prise d'appel (epic ORGA-493).

Describe your changes

Checklist tests

Issue ticket number and link

Checklist before requesting a review (magic string, indentation, comment/documentation...)

• I have detailed the tests to do in my feature/fix in order to prevent consequents regressions (must specify in Checklist tests)
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (API Doc etc...) - (must specify in Description for target version)
• If it is a consequent feature, I have added thorough tests.
• I have added tests that prove my fix is effective or that my feature works
• Any dependent changes have been added to this project (must specify in Description)