Release 0.2609.4

This release improves static-site deployment pages and keeps site routes synchronized more reliably.

Fixes:

• Fixed the site deployment detail page and its handling of deployment data
• Added durable retries when site route publication is temporarily unavailable
• Improved synchronization between the active deployment and published site routes
• Improved route cleanup and retry handling when a site is deleted
• Improved cache-purge handling so temporary delivery-service failures can be retried