Deploy and finalize Sanity schema rollout for press CMS

[sean-lai-sh]

Problem

The press feature now depends on new Sanity types (pressPost, pressSpotlight), but the remote schema/content workflow is not fully aligned yet. Content can be partially seeded, but schema-aware operations and the fixed-ID spotlight singleton are not fully productionized until the schema rollout is complete.

Scope

• Deploy the updated Studio schema that includes pressPost and pressSpotlight
• Ensure pressSpotlight is a true singleton with the fixed document ID expected by the desk structure and frontend query
• Seed or migrate the initial spotlight posts with valid cover images and publish state
• Confirm homepage Spotlight and /press Spotlight resolve from the same canonical singleton content
• Document the editor workflow for creating, featuring, and publishing press posts

Acceptance Criteria

• The deployed schema recognizes pressPost and pressSpotlight
• Editors can open and manage the spotlight singleton in Studio
• The initial four spotlight posts exist with valid required fields
• The public site can resolve spotlight content without falling back to hardcoded placeholders