SQLite provider removed from service collection and runtime database options. Microsoft.Data.Sqlite package added to Jellyfin.Server for migration routines (SQLite → PostgreSQL). Migration service updated to always use PostgreSQL. SqliteExtensions restored for migration helpers. SQLite migration test deleted. Documentation added to explain migration-only support and deployment impact. No breaking changes for users migrating from SQLite; deployment size increases (~68 MB) for cross-platform SQLite DLLs.
Refactored all C# test files to use explicit namespace declarations and moved all using directives inside the namespace block for consistency. Updated assembly info and cache files to reflect the new build. Adjusted MvcTestingAppManifest.json to use fully qualified assembly names. No functional changes; all updates are related to code style, organization, and project metadata.