feat: initial release v0.3.0

- Support 9 chart types: line, bar, pie, scatter, bubble, donut, mixed, polar, radar
- Multi-format output: ANSI, SVG, PNG, Markdown
- Go + Fiber + gonum/plot
- Docker support
- Morandi color palette

internal/renderer/renderer.go

@@ -0,0 +1,14 @@
+package renderer
+
+import "github.com/picoclaw/chart/internal/types"
+
+type Renderer interface {
+	Render(chart *types.Chart) ([]byte, error)
+}
+
+type RenderResult struct {
+	Text string
+	ANSI string
+	SVG  string
+	PNG  []byte
+}