fix(server): recover missing session routes gracefully

[dzianisv]

Report

Opening the stated session URL returns a 404: Session not found: ses_00df9fc0dffeX34w9J1V1NLw7X.

Investigation

• Verify live server health and session inventory.
• Determine whether workspace routing or a missing/purged session is responsible.
• Document an immediate safe recovery path.
• Implement and validate a product fix if server or UI behavior is defective.

Status

Investigating.