Function apply_init_pragmas 

pub fn apply_init_pragmas(conn: &Connection) -> Result<(), AppError>

Applies one-time PRAGMAs on a freshly opened connection (e.g. auto_vacuum).

Calls apply_connection_pragmas internally and then sets wal_autocheckpoint. Must be called once per database file, not once per connection.

Errors

Returns Err when any PRAGMA execution fails.