v5.2.1

Changed

• Select the explicit null App Configuration label instead of treating None as a wildcard, preserving the existing labeled-setting precedence.
• Add opt-in APP_CONFIG_TLS_COMPATIBILITY for verified App Configuration and Key Vault HTTPS transport; the default remains false, and enabling it requires KEY_VAULT_URI.
• Preserve managed identity, certificate and hostname verification, custom CA trust, and authentication-versus-availability error handling.

Validation

• Offline regression tests, the complete unit suite, frontend build, CodeQL, and all protected quality checks passed for the reconciled release.
• No Azure deployment or environment validation was performed for this release.