Let the AI Suggest Markup Cells

[jlewi]

Once we fix #168 we will be able to render markup cells as ghost cells. So we could potentially have the AI start generating ghost markup cells.

This requires thinking through and changing a number of things.

1. Currently, we only trigger if the selected cell is a markup cell

   foyle/app/pkg/agent/agent.go

   Line 615 in b4874f5

   func shouldTrigger(doc *v1alpha1.Doc, selectedIndex int32) bool {

   • This was a cost saving measure. Now that we are using gpt4o-mini which is pretty cheap we should be able to remove this

2. We postprocess the completion to only return the code block
   

   foyle/app/pkg/agent/agent.go

   Line 559 in b4874f5

   func postProcessBlocks(blocks []*v1alpha1.Block) ([]*v1alpha1.Block, error) {

Its not entirely clear how we should change the post-processing. There's a couple different situations to consider

1. If the selected cell is a code cell; it might be reasonable to try to insert a markup cell that reasons about the results and figures out what to do next

2. If the current cell is a code cell; it sometimes will be reasonable to respond with a code cell that provides a plan about how to accomplish some task.

   • This would be useful when posing a question such as "Why isn't my application working."

[jlewi]

Fixed by #285