Initial commit: BAF Lakehouse fraud detection pipeline

End-to-end LightGBM fraud detection pipeline built as an R package,
orchestrated by targets with data stored in MinIO via Apache Arrow.
Includes 6-layer Lakehouse architecture, class imbalance tournament,
formally tuned hyperparameters (PR-AUC 0.198), and Quarto RevealJS slides.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

man/convert_to_parquet.Rd

@@ -0,0 +1,41 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/functions.R
+\name{convert_to_parquet}
+\alias{convert_to_parquet}
+\title{Convert BAF CSV to partitioned Parquet in MinIO (S3)}
+\usage{
+convert_to_parquet(from_prefix, to_prefix, bucket_name = "baf-fraud")
+}
+\arguments{
+\item{from_prefix}{Character. Prefix/key under the bucket containing CSVs (e.g. \code{"01_raw"}).}
+
+\item{to_prefix}{Character. Prefix/key under the bucket to write Parquet dataset (e.g. \code{"02_intermediate"}).}
+
+\item{bucket_name}{Character. Bucket name. Default \code{"baf-fraud"}.}
+}
+\value{
+A character string giving the destination dataset prefix (typically \code{to_prefix}).
+}
+\description{
+Reads \code{Base.csv} from a MinIO/S3 bucket prefix (e.g., \code{"01_raw"}) and writes a
+Hive-style partitioned Parquet dataset to another prefix (e.g., \code{"02_intermediate"}),
+partitioned by \code{variant} (e.g., \verb{variant=Base/part-*.parquet}).
+}
+\details{
+Connection settings are taken from environment variables:
+\itemize{
+\item \code{BAF_ENDPOINT} (e.g. \code{"minio:9000"} or \code{"192.168.4.xx:9000"})
+\item \code{BAF_KEY} (MinIO access key)
+\item \code{BAF_SECRET} (MinIO secret key)
+}
+}
+\examples{
+\dontrun{
+Sys.setenv(
+  BAF_ENDPOINT = "minio:9000",
+  BAF_KEY      = "YOUR_ACCESS_KEY",
+  BAF_SECRET   = "YOUR_SECRET_KEY"
+)
+convert_to_parquet(from_prefix = "01_raw", to_prefix = "02_intermediate", bucket_name = "baf-fraud")
+}
+}