Show tabs in left rail as collapsible sub-items under tasks

[benjaminshoemaker]

Summary

Tabs (conversations) within a task should be visible in the left sidebar rail as sub-items nested under their parent task, with full parity to the controls currently available in the tab bar and task list.

Current behavior

Tabs are only visible in the tab bar within the task view. The left rail shows projects and tasks, but not individual tabs/conversations.

Desired behavior

Left rail structure

The hierarchy should be:

▾ Project Name
    ▾ Task Name          [+]
        🤖 Tab Name      [×]
        🟣 Tab Name      [×]
    ▸ Another Task       [+]

• Tabs are indented under their parent task at the same level that tasks are indented relative to the project name
• Each task gets a collapse/expand arrow (▸/▾), matching the behavior projects currently have
• Each task gets a [+] button, matching the behavior projects currently have — clicking it opens a new tab within that task

Tab controls

Each tab in the left rail should have:

• Close button (×) — same as the current tab bar close control
• Right-click context menu with at minimum a Rename option, matching the right-click menu tasks currently have
• Agent icon — show the icon of the agent/provider being used (Claude, Codex, etc.)

Rename behavior

• Tabs should be renamable via the right-click context menu
• Note: Auto-generate short descriptive names for tasks and tabs #2123 introduces auto-generated names for tasks and tabs — the rename UX here should account for names that were auto-generated vs. manually set. Consider whether renaming should "pin" the name (prevent future auto-renames) or if that distinction is unnecessary.

Dependencies / related

• Auto-generate short descriptive names for tasks and tabs #2123 — Auto-generate short descriptive names for tasks and tabs (the rename flow here should be consistent with auto-naming)

[benjaminshoemaker]

I should note - this may be difficult; it may not - I don't know - it is just a feature request without knowledge of the challenges or relative priority.

[benjaminshoemaker]

Implementation note: There's an existing conversation list in the task-local right sidebar (TaskSidebar → SidebarConversationsList), which renders inside the task view as a resizable panel. This proposal adds conversations to the global left rail — both can coexist, but the implementer should keep behavior consistent between them (rename, context menu, icons, etc.).

[Aarekaz]

@benjaminshoemaker , I might give this a jab.

[rabanspiegel]

@benjaminshoemaker thank you for opening this issue! And @Aarekaz thank you for your interest in contributing and taking a stab at it! I am curious to see your implementation. Transparently, we're internally working on the workspace / task / conversation architecture to be best set up for supporting local as well as remote workspaces / tasks via BYOI or our own Emdash Cloud. Hence, while I am interested to see how you envision the UX of rendering conversations under the tasks in the sidebar, it's unlikely that we'll merge anything pertaining to that architecture at this point as our internal work will naturally lead to a reorg of the sidebar as well.

[Aarekaz]

Thanks for being upfront @rabanspiegel , makes sense to hold while the rework's in flight. In case any of it's useful as you redo the sidebar, here's the direction I was
going:

• Only show conversation rows when a task has 2 or more conversations. Single-conversation tasks (which is most of them) stay flat.
• Drop the per-task + button. There's already a + in the in-task tab bar and a right-click "new conversation", so putting one on every sidebar row felt like noise for something you rarely do.
• Conversations only. No diff or file tabs — those are scoped to what you're looking at inside the task, not the task itself.
• Default collapsed. Only auto-expand when you click into a conversation inside that task.
• Order mirrors the tab bar, read-only. Reordering still happens in the tab bar.

I was gonna take a dab at #2123 but it seems like there is work going on there too

[rabanspiegel]

Thanks for these thoughts, @Aarekaz ! And agreed, I imagine the final output will look very similar to what you're proposing

[Aarekaz]

Yup! Excited for what you guys put out. I am pausing my work on that PR right now.