feat: add MouseDown/MouseUp methods to InteractiveBrowser

Enables drag operations (mousedown → mousemove → mouseup) needed for
slider captchas and other drag-based interactions.

Closes #79

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

interactive.go

@@ -23,6 +23,10 @@ type InteractiveBrowser interface {
 
 	// MouseClick clicks at the given coordinates with the specified button ("left", "middle", "right").
 	MouseClick(x, y float64, button string) error
+	// MouseDown presses the mouse button at the given coordinates without releasing.
+	MouseDown(x, y float64, button string) error
+	// MouseUp releases the mouse button at the given coordinates.
+	MouseUp(x, y float64, button string) error
 	// MouseMove moves the mouse to the given coordinates.
 	MouseMove(x, y float64) error
 	// MouseWheel scrolls by the given delta.
@@ -156,6 +160,38 @@ func (ib *interactiveBrowser) MouseClick(x, y float64, button string) error {
 	return ib.page.Mouse().Click(x, y, playwright.MouseClickOptions{Button: btn})
 }
 
+func (ib *interactiveBrowser) MouseDown(x, y float64, button string) error {
+	if err := ib.page.Mouse().Move(x, y); err != nil {
+		return err
+	}
+	var btn *playwright.MouseButton
+	switch button {
+	case "right":
+		btn = playwright.MouseButtonRight
+	case "middle":
+		btn = playwright.MouseButtonMiddle
+	default:
+		btn = playwright.MouseButtonLeft
+	}
+	return ib.page.Mouse().Down(playwright.MouseDownOptions{Button: btn})
+}
+
+func (ib *interactiveBrowser) MouseUp(x, y float64, button string) error {
+	if err := ib.page.Mouse().Move(x, y); err != nil {
+		return err
+	}
+	var btn *playwright.MouseButton
+	switch button {
+	case "right":
+		btn = playwright.MouseButtonRight
+	case "middle":
+		btn = playwright.MouseButtonMiddle
+	default:
+		btn = playwright.MouseButtonLeft
+	}
+	return ib.page.Mouse().Up(playwright.MouseUpOptions{Button: btn})
+}
+
 func (ib *interactiveBrowser) MouseMove(x, y float64) error {
 	return ib.page.Mouse().Move(x, y)
 }