Desktop: Sidebar subsessions support

[dbpolito]

Adding support for showing subsessions on sidebar, collapsing similar to project:

Right now i kept a similar behavior from project, clicking the row expand / collapse and navigate to it.

[adamdotdevin]

So, I used to show child sessions in the sidebar, but tbh, I don't think they belong there. I would accept a PR for making the Task tool description a link to the child session, though. That was my plan, just hadn't gotten to it.

[dbpolito]

@adamdotdevin hmm, i think the general ux of navigating between subsessions aren't great on both desktop and tui...

I opened #4564 a while back, there is also #4865 that brings them to the sidebar...

Let's think about some other options:

1. Separate the expand / collapse behavior so you really need to click on the icon to open / view sub sessions, that way people can easily ignore sub sessions?
2. Maybe add a button on the new status bar? x subsessions? you click, we open a modal with a list of sessions? similar to my PR on TUI? that would be somehow consistent, we could even have the same /subagent-sessions command to open the dialog (or maybe just the command is enough)

I think clicking the task tool description is fine but then you would navigate to it, how you would return to the parent session? You would need to find it back on the sidebar? Feel a bit weird

[diogosalazar]

@adamdotdevin this would be good UX to be able to see at a glance how many sub sessions are active or can be resumed. Useful in workflows involving multiple specialist sub agents

[longsman]

@adamdotdevin hmm, i think the general ux of navigating between subsessions aren't great on both desktop and tui...

I opened #4564 a while back, there is also #4865 that brings them to the sidebar...

Let's think about some other options:

1. Separate the expand / collapse behavior so you really need to click on the icon to open / view sub sessions, that way people can easily ignore sub sessions?
2. Maybe add a button on the new status bar? x subsessions? you click, we open a modal with a list of sessions? similar to my PR on TUI? that would be somehow consistent, we could even have the same /subagent-sessions command to open the dialog (or maybe just the command is enough)

I think clicking the task tool description is fine but then you would navigate to it, how you would return to the parent session? You would need to find it back on the sidebar? Feel a bit weird

So as of now, there's a link in the task tool description, that takes you to the subagent session, and I found the small left-arrow button at the breadcrumb part at the top, hovering over it says 'go back to parent session'.

My default reaction is that I do wish I could see it in the sidebar, but like OP, I agree with seeing if there's some sort of compromise. I agree with @dbpolito maybe theres a way to 'reveal' it for those fully intent on revealing it, even if it's somewhat hidden, I think I'd accept that cost.

Lets say we accept sub-sessions dont belong in the sidebar, ok thats fine. can we otherwise get somewhere else that shows <-- ,whether that's the breadcrumb or even a hidden command that'll reveal all sub-sessions?

I suppose I need to help by giving more color to the purpose of subagent session visibility. Perhaps it helps to say that seeing the 'shape' of subagent usage and the history of subagents in a session mainly comes into play when reviewing the overall workflow that just happened, instead of it being relevant to the specific task(s) of the project itself. I dont really agree with amp's approach with doing some crazy flowchart, but here's an example of how i'd currently experience OC desktop if I want to review a workflow to assess the quality of subagents and task delegation:

1. I'm thinking of making adjustments, change models or system prompts for a subagent. Let me go to yesterday's session to see how my planning agent behaves.
2. open opencode desktop for more casual, relaxed, clickable browsing and reviewing.
3. click on project, click on specific session
4. ok i gotta look for the subagent...
   4a. its not in sidebar, let me double check this session actually used subagents
   4b. scroll up/skipp through timeline
   4c. ok the timeline chapter description seems like it shows a task
   4d. ok I gotta click on show steps to reveal task
5. there it is. click.
6. read it, review it, ok how do i go back?
7. Theres and arrow, whats that? hover, ok this goes back to parent.
8. need to look at other subagent I know I used. (repeat step 4)
9. I wonder what other tasks got delegated...

sorry for verbose I know this has been debated for quite a while but I never did a good job explaining what I'd like sub-session list visibility for.

[dbpolito]

So a couple of more options we could go:

Currently on the breadcrumb we can see other session, tbh i never used that, but if we add another layer, a new breadcrumb path, clickable that we could change between parent / child sessions there?

Another option is, i introduced this new concept or more things on the right panel, maybe we could have something there too: #7223

[longsman]

Yeah I think something up at the breadcrumb might just at least serve as some visual cue, like:
opencode / parent-session-title / Sub-Sessions
and of course sub-sessions is clickable to reveal a list of children sessions, or sub-sessions wouldnt even show up if there are none. My hope is that this addition would be very non-invasive unless there are other plans for the entire idea of breadcrumb up there seems like people dont notice it or use it.

I dont mind more stuff in that right panel as suggested in that pr either, in fact, maybe being encouraged to see parent + child session side by side would really make things more interesting.