feat: add steps parameter to MouseMove for smooth drag gestures

Makes MouseMove accept an optional steps variadic parameter that maps
to Playwright's MouseMoveOptions.Steps, generating intermediate
mousemove events for human-like drag behavior.

Closes #81

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

interactive.go

@@ -27,8 +27,9 @@ type InteractiveBrowser interface {
 	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
+	// MouseMove moves the mouse to the given coordinates. An optional steps parameter
+	// controls how many intermediate mousemove events are generated (default 1).
+	MouseMove(x, y float64, steps ...int) error
 	// MouseWheel scrolls by the given delta.
 	MouseWheel(deltaX, deltaY float64) error
 
@@ -192,8 +193,12 @@ func (ib *interactiveBrowser) MouseUp(x, y float64, button string) error {
 	return ib.page.Mouse().Up(playwright.MouseUpOptions{Button: btn})
 }
 
-func (ib *interactiveBrowser) MouseMove(x, y float64) error {
-	return ib.page.Mouse().Move(x, y)
+func (ib *interactiveBrowser) MouseMove(x, y float64, steps ...int) error {
+	var opts playwright.MouseMoveOptions
+	if len(steps) > 0 && steps[0] > 1 {
+		opts.Steps = playwright.Int(steps[0])
+	}
+	return ib.page.Mouse().Move(x, y, opts)
 }
 
 func (ib *interactiveBrowser) MouseWheel(deltaX, deltaY float64) error {

promote_test.go

@@ -15,7 +15,7 @@ func (m mockInteractiveBrowser) URL() string                            { return
 func (m mockInteractiveBrowser) MouseClick(float64, float64, string) error { return nil }
 func (m mockInteractiveBrowser) MouseDown(float64, float64, string) error  { return nil }
 func (m mockInteractiveBrowser) MouseUp(float64, float64, string) error    { return nil }
-func (m mockInteractiveBrowser) MouseMove(float64, float64) error          { return nil }
+func (m mockInteractiveBrowser) MouseMove(float64, float64, ...int) error  { return nil }
 func (m mockInteractiveBrowser) MouseWheel(float64, float64) error      { return nil }
 func (m mockInteractiveBrowser) KeyboardType(string) error              { return nil }
 func (m mockInteractiveBrowser) KeyboardPress(string) error             { return nil }