v0.5.25

Added

• Add QuackDB.Ecto.Decimal for exact decimal comparisons with explicit precision and scale, usable through Ecto parameterized types and type/2. Bare :decimal casts use DuckDB's DECIMAL(18,3) default and silently round values such as 9.5001.
• Add contains/3 for literal case-insensitive text containment with case_sensitive: false; matching lowercases both operands in DuckDB and treats %, _, and backslashes literally. contains/2 behavior is unchanged.