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/types/chart.go

@@ -0,0 +1,61 @@
+package types
+
+type ChartType string
+
+const (
+	ChartTypeLine    ChartType = "line"
+	ChartTypeBar     ChartType = "bar"
+	ChartTypePie     ChartType = "pie"
+	ChartTypeScatter ChartType = "scatter"
+	ChartTypeBubble  ChartType = "bubble"
+	ChartTypeDonut   ChartType = "donut"
+	ChartTypeMixed   ChartType = "mixed"
+	ChartTypePolar   ChartType = "polar"
+	ChartTypeRadar   ChartType = "radar"
+)
+
+type ChartRequest struct {
+	Type    ChartType     `json:"type"`
+	Title   string        `json:"title"`
+	Data    ChartData     `json:"data"`
+	Options *ChartOptions `json:"options,omitempty"`
+}
+
+type ChartData struct {
+	Labels   []string      `json:"labels"`
+	Datasets []Dataset     `json:"datasets"`
+	Options  *ChartOptions `json:"options,omitempty"`
+}
+
+type Dataset struct {
+	Name   string    `json:"name"`
+	Values []float64 `json:"values"`
+	Color  string    `json:"color,omitempty"`
+}
+
+type ChartOptions struct {
+	Width  int `json:"width,omitempty"`
+	Height int `json:"height,omitempty"`
+}
+
+type ChartResponse struct {
+	ChartID  string `json:"chart_id"`
+	Text     string `json:"text"`
+	ANSI     string `json:"ansi"`
+	SVG      string `json:"svg"`
+	PNGURL   string `json:"png_url"`
+	Markdown string `json:"markdown"`
+}
+
+type ErrorResponse struct {
+	Error string `json:"error"`
+}
+
+type Chart struct {
+	ID    string
+	Type  ChartType
+	Title string
+	Data  ChartData
+	SVG   []byte
+	PNG   []byte
+}