GET /api/media-sources threw on any empty database: with zero result
rows, Microsoft.Data.Sqlite reports the COUNT(*) column as BLOB, so
Dapper generated a (long, byte[]) deserializer that cannot match
LibraryItemCount(long, long). Replaced the Dapper query with EF LINQ
GroupBy (provider-agnostic, no schema inference) and added an
empty-database regression test.
Also carries the Scriban.Signed 6.5.2 -> 7.2.5 bump (GHSA-5wr9-m6jw-xx44,
PR #137) so this branch builds; redundant once #137 lands on main.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>