Add username support for Azure DevOps

[TedTschopp]

Azure DevOps username / profile validation

Category: dev

Goal: Detect whether an Azure DevOps public profile/identity exists for a given name.

Notes:

• Azure DevOps has both organizations and user identities; this issue is specifically about user or personal profiles that can act like a handle.
• The exact public URL pattern may require investigation (e.g. dev.azure.com and visualstudio.com legacy URLs).

Implementation suggestions:

• Investigate how Azure DevOps exposes public profiles for individuals (if any consistent URL exists).
• If a stable URL exists for user profiles, implement a validator using status_validate() or generic_validate().
• Document any limitations (e.g. if only organizations can be reliably checked).

Implementation notes:

• Place module in dev/azure_devops.py.
• Implement validate_azure_devops(username: str).
• Reuse common HTTP helpers from core/orchestrator.py.