mopac-pdf v0: markdown to beautiful PDFs via digest-pinned typst

Go CLI that turns the markdown currency of this stack (Redmine notes,
Discourse posts, briefing output) into typeset PDFs: two embedded typst
templates (report with title page/TOC/headers, dense brief), front-matter
(title/subtitle/author/date/classification/template), GFM tables, and
bar charts rendered in pure Go (go-chart) from fenced chart data blocks.
Engine is a prebuilt typst 0.15.1 container pinned by digest and run
--network none; PDF bytes to stdout or -o. Exit codes 0/1/2.

All dev in docker (dev.sh/Makefile); unit tests + golden typst fixtures
plus a host-side smoke against the real engine container.

Generated with Crush

Assisted-by: Crush:glm-5.2

vendor/github.com/wcharczuk/go-chart/v2/drawing/painter.go

@@ -0,0 +1,31 @@
+package drawing
+
+import (
+	"image"
+	"image/color"
+
+	"golang.org/x/image/draw"
+	"golang.org/x/image/math/f64"
+
+	"github.com/golang/freetype/raster"
+)
+
+// Painter implements the freetype raster.Painter and has a SetColor method like the RGBAPainter
+type Painter interface {
+	raster.Painter
+	SetColor(color color.Color)
+}
+
+// DrawImage draws an image into dest using an affine transformation matrix, an op and a filter
+func DrawImage(src image.Image, dest draw.Image, tr Matrix, op draw.Op, filter ImageFilter) {
+	var transformer draw.Transformer
+	switch filter {
+	case LinearFilter:
+		transformer = draw.NearestNeighbor
+	case BilinearFilter:
+		transformer = draw.BiLinear
+	case BicubicFilter:
+		transformer = draw.CatmullRom
+	}
+	transformer.Transform(dest, f64.Aff3{tr[0], tr[1], tr[4], tr[2], tr[3], tr[5]}, src, src.Bounds(), op, nil)
+}