Function parse_db_md 

pub fn parse_db_md(text: &str, file: &Path) -> Result<Config, ParseError>

Parse a store’s DB.md file into a Config: the ## Agent instructions prose, ## Policies (### Frozen pages + ### Ignored types), and ## Schemas (### <type> field-bullet blocks). Unrecognized sections are ignored; absent sections leave their Config fields at default.