feat: implement prepareSqlitePath function and add tests for database path handling

src/db/sqlitePath.ts

@@ -0,0 +1,12 @@
+import { mkdirSync } from "node:fs";
+import { dirname } from "node:path";
+
+export function prepareSqlitePath(databaseUrl: string): string {
+  const sqlitePath = databaseUrl.replace(/^file:/, "");
+
+  if (sqlitePath !== ":memory:") {
+    mkdirSync(dirname(sqlitePath), { recursive: true });
+  }
+
+  return sqlitePath;
+}