Fix Azure TLS Configuration

My production web apps are down right now because the pages have become inaccessible due to net::ERR_CERT_DATE_INVALID errors. The root cause points to incorrectly configured TLS certificates on the Web Services tier. The Application Gateway reports all backend pools in Healty Status

Here is what I need in very short order:

• Diagnose and correct the TLS bindings for every Web Service so that browsers load each site without error.
• Validate the certificate chain and SNI settings on the Application Gateway and propagate any required fixes.
• Confirm that AD B2C callbacks and custom domains present the right certificate and handshake cleanly.
• Walk me through the changes in Azure Portal / Azure CLI or ARM so I can repeat the process at the next renewal.

I will accept the work when all sites load over HTTPS with no certificate warnings, A-grade results show in SSL Labs, and traffic flows normally through the gateway.

If you live inside Azure Key Vault, App Gateway, Front Door, and AD B2C every day, this should be straightforward. I can grant RBAC access immediately so we can get the business back online.