Function open_stores_and_migrate 

pub fn open_stores_and_migrate(
    config: &Config,
    version: &str,
    build_time: &str,
) -> Stores

Step 4: Initialize backend (matching Go cmd/server/main-server.go:374-590). Sets up the data directory, runs in-process migrations, opens every SQLite-backed store, attaches the shared/global registries, and performs the various one-time startup seed/repair passes.