Add obea.fr and kanbios.fr domains to allowed authentication domains

[NicolasLMP]

Title: Add obea.fr and kanbios.fr domains to allowed authentication domains

Why:
As a user with an obea.fr or kanbios.fr email address, I need to be able to authenticate and access Isschat, as currently only isskar.fr domain users can log in to the application.

DoD:

• Update AZURE_ALLOWED_DOMAINS environment variable to include obea.fr and kanbios.fr
• Test authentication with obea.fr email addresses
• Test authentication with kanbios.fr email addresses
• Verify isskar.fr authentication still works correctly
• Update deployment configuration with new allowed domains
• Document domain access policy for future reference

How:

• Update allowed_domains configuration from "isskar.fr" to "isskar.fr,obea.fr,kanbios.fr"
• Modify AZURE_ALLOWED_DOMAINS environment variable in deployment configuration
• Test login flow with users from each allowed domain
• Verify Azure AD group membership validation works for all domains
• Update authentication documentation with new domain policy
• Deploy updated configuration to production environment