The local database is stored as a single file in the computer's file system. The runtime is responsible for creation, retrieval and manipulation of data in this database file.

The combination of local storage, cross-platform (including tablets), and short development effort I think narrow down your choice to likely 0.

A new SQL Server 2025 feature lets organizations run vector-based semantic searches on their own data, connecting to local or cloud-hosted AI models without relying on massive general-purpose LLMs.

Microsoft this week announced various Azure SQL Database improvements, including migration, high-availability and information protection options.

Some of the best open source SQL Clients for Database Management are Sqlectron, SQuirrel SQL client, SQL Chat, OmniDB, HeidiSQL,Falcon, etc.