This script shows up in Layers > All Layers to image size.

Would it be possible to make it show up in the Layers right-click menu, also?

Not sure about "also"
RobA gradients scripts install usually in the right click gradient menu i believe would be possible use same method to install in the layer manu
(i mean use as template the path of the script but replacing "gradient" with "layer")

Well ,if you need more details you may want to wait the GC scripts guru, that is what i would try

Change the string "<Image>/Layer/All Layers to Image Size" to "<Layers>/All Layers to Image Size".

If you want the command to appear in both places, you will need to use the 'script-fu-menu-register' procedure. An example of this can be seen in my Align Down script.

Thank you, saulgoode. For some reason I like that right-click menu better than the Layer drop down in the image menu. Just a strange quirk of mine. Got it fixed.

I like to register scripts for layers in both locations, as suggested by saulgoode. That way it is easier to find for any type of user

-Rob A>

Also, if the command is in the context (right-click) menu then you are sure about which layer/channel/path the script is working with. However, if the command is ONLY in the context menu then you can't assign a keyboard shortcut to it -- the command must be added to the image window menus to do that.