V2 reorg

[jaydestro]

This pull request makes several improvements to the conference agenda and speaker sections, including adding new session and keynote entries, updating video URLs, and enhancing speaker profile capabilities. The most notable changes are the addition of new sessions and keynotes, support for YouTube links in speaker profiles, and expanded preview parameter support for video release logic.

Conference agenda and session updates:

• Added a new session, "Powering Azure Cosmos DB with AMD EPYC" by Andrew Ruffin, to the agenda and included his full speaker profile in speakers2026.json. [1] [2]
• Updated the video URL for "Cosmos DB Best Practices — A Lesson from Spacely Sprockets" and "Querying and Indexing in Azure Cosmos DB: The Complete Guide" to their correct YouTube links. [1] [2]
• Added two new on-demand keynote interviews: one with Guillermo Rauch (Vercel) and one with Jonathan Lee (OpenAI).

Speaker profile enhancements:

• Introduced a new youtube field to the Speaker interface and updated the speaker modal to display YouTube links if available. [1] [2] [3]
• Moved Tural Suleymani's YouTube channel from the blog field to the new youtube field in his speaker profile.

Video release logic improvements:

• Expanded the video release preview logic to support both ?releaseNow and ?streamNow query parameters for testing and previewing video releases.