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/save_report_figure.Rd

@@ -0,0 +1,31 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/functions.R
+\name{save_report_figure}
+\alias{save_report_figure}
+\title{Save a report figure artifact}
+\usage{
+save_report_figure(
+  plot,
+  filename,
+  out_dir = "reports/figures",
+  width = 12,
+  height = 6.75,
+  dpi = 300
+)
+}
+\arguments{
+\item{plot}{A ggplot object.}
+
+\item{filename}{Character. Output filename, e.g. \code{"fig_fraud_by_month.png"}.}
+
+\item{out_dir}{Character. Output directory. Default \code{"reports/figures"}.}
+
+\item{width, height, dpi}{Numeric. Passed to \code{ggplot2::ggsave()}.}
+}
+\value{
+Character. Normalized path to the saved file.
+}
+\description{
+Saves a ggplot object to \code{reports/figures/}.
+Intended for use in \code{targets} pipelines as a file-producing target.
+}