Configurable grid + snap-to-grid in the layout system (#45)

Closes #44. Two independent grids (garden + per-bed), each with a size and a snap toggle; snapping defaults off. See PR #45 for details.

Co-authored-by: Steve Dudenhoeffer <[email protected]>

internal/api/objects.go

@@ -27,6 +27,8 @@ type objectCreateRequest struct {
 	Plantable   *bool           `json:"plantable"`
 	Color       *string         `json:"color"`
 	Props       json.RawMessage `json:"props"`
+	GridSizeCM  float64         `json:"gridSizeCm"`
+	SnapToGrid  bool            `json:"snapToGrid"`
 	Notes       string          `json:"notes"`
 }
 
@@ -35,7 +37,8 @@ func (r objectCreateRequest) toInput() service.ObjectInput {
 		Kind: r.Kind, Name: r.Name, Shape: r.Shape,
 		XCM: r.XCM, YCM: r.YCM, WidthCM: r.WidthCM, HeightCM: r.HeightCM,
 		RotationDeg: r.RotationDeg, ZIndex: r.ZIndex, Plantable: r.Plantable,
-		Color: r.Color, Props: propsFromRaw(r.Props), Notes: r.Notes,
+		Color: r.Color, Props: propsFromRaw(r.Props),
+		GridSizeCM: r.GridSizeCM, SnapToGrid: r.SnapToGrid, Notes: r.Notes,
 	}
 }
 
@@ -54,6 +57,8 @@ type objectUpdateRequest struct {
 	Plantable   *bool           `json:"plantable"`
 	Color       json.RawMessage `json:"color"`
 	Props       json.RawMessage `json:"props"`
+	GridSizeCM  *float64        `json:"gridSizeCm"`
+	SnapToGrid  *bool           `json:"snapToGrid"`
 	Notes       *string         `json:"notes"`
 	Version     int64           `json:"version" binding:"required,min=1"`
 }
@@ -67,7 +72,8 @@ func (r objectUpdateRequest) toPatch() (service.ObjectPatch, error) {
 	return service.ObjectPatch{
 		Name: r.Name, XCM: r.XCM, YCM: r.YCM, WidthCM: r.WidthCM, HeightCM: r.HeightCM,
 		RotationDeg: r.RotationDeg, ZIndex: r.ZIndex, Plantable: r.Plantable,
-		SetColor: setColor, Color: color, SetProps: setProps, Props: props, Notes: r.Notes,
+		SetColor: setColor, Color: color, SetProps: setProps, Props: props,
+		GridSizeCM: r.GridSizeCM, SnapToGrid: r.SnapToGrid, Notes: r.Notes,
 	}, nil
 }