feat: add annotation tool settings menus

internal/application/annotation.go

@@ -22,11 +22,12 @@ import (
 // Annotation describes a user-drawn mark relative to the selected screenshot.
 // Coordinates are logical pixels in the same coordinate system as the overlay.
 type Annotation struct {
-	Tool     string  `json:"tool"`
-	Color    string  `json:"color"`
-	Points   []Point `json:"points"`
-	Text     string  `json:"text,omitempty"`
-	FontSize float64 `json:"fontSize,omitempty"`
+	Tool        string  `json:"tool"`
+	Color       string  `json:"color"`
+	Points      []Point `json:"points"`
+	Text        string  `json:"text,omitempty"`
+	StrokeWidth float64 `json:"strokeWidth,omitempty"`
+	FontSize    float64 `json:"fontSize,omitempty"`
 }
 
 type Point struct {
@@ -66,7 +67,11 @@ func ApplyAnnotationsWithScale(pngBytes []byte, annotations []Annotation, scaleX
 		if err != nil {
 			c = color.RGBA{R: 59, G: 130, B: 246, A: 255}
 		}
-		width := int(math.Max(2, math.Round(3*strokeScale)))
+		strokeWidth := ann.StrokeWidth
+		if strokeWidth <= 0 {
+			strokeWidth = 3
+		}
+		width := int(math.Max(1, math.Round(strokeWidth*strokeScale)))
 		switch ann.Tool {
 		case "pen":
 			drawPolyline(dst, ann.Points, scaleX, scaleY, width, c)