Warn when "Custom" binding username claim becomes unsupported

[Patryk Mroczko (patmr7)]

No description provided.

[Copilot]

Pull request overview

This PR adds an admin-facing warning when the “Binding username claim” setting is stored as Custom but becomes unsupported under the currently configured IdP type when local_o365 user sync is enabled, helping prevent silent misconfiguration after settings changes.

Changes:

• Add a new validation function to warn admins when a stored “Custom” binding username claim becomes unsupported.
• Invoke this validation during OIDC auth settings validation.
• Trigger this validation when local_o365 user sync settings are updated, and add the corresponding language string.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
local/o365/settings.php	Attaches an updated-callback to user sync settings to run the new binding-claim validation when sync settings change.
auth/oidc/lib.php	Adds auth_oidc_validate_binding_username_claim() and calls it from auth settings validation to emit a warning when configuration becomes unsupported.
auth/oidc/lang/en/auth_oidc.php	Adds the warning message string shown to admins.

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