TUI: Parent session appears stuck "loading" when subagent is blocked (waiting user input / hanging tool call); lack of visibility and recovery UX #10802

Problem

When running a workflow that spawns subagents (Task/subtask), the parent session UI can appear to be stuck "loading" indefinitely. From the parent session, it's not clear whether:

• a subagent is waiting for user input, or
• a tool call inside a subagent is hanging (e.g., webfetch), or
• something is actually deadlocked.

This creates a "feels frozen" experience because the parent session shows only something like "N toolcalls" and doesn't surface what it's waiting on.

Expected

• Parent session should clearly show which subagent is currently running/blocking.
• If the subagent is waiting for user input, parent should indicate "waiting for user input" (and ideally allow replying without manually switching sessions).
• If a tool call is in progress, parent should show the tool name + target (e.g., URL for webfetch) and elapsed time, and provide a clear cancel/interrupt affordance.
• Ideally, auto-return to parent and/or show a status banner when subagent completes / blocks.

Actual

• Parent session stays in a loading-looking state for a very long time.
• The only way to understand what's happening is to manually navigate into subagent sessions (ctrl+x right) and inspect them.
• In my case, one subagent was waiting for an explicit user reply (e.g., asking "should I continue searching?"), while the parent still looked like "loading".
• Another subagent showed a hanging webfetch (red tool label) without any visible timeout/progress on the parent.

Repro Steps

1. Run OpenCode in TUI inside a repo/project.
2. Trigger a workflow that spawns subagents (e.g., a custom /deep-research ... command that uses subtask: true and calls Task to run dr-web / dr-repo).
3. Observe parent session shows toolcalls and appears to be loading indefinitely.
4. Press ctrl+x then right to view subagent sessions.
5. Observe subagent is blocked either on:
   • waiting for user input, or
   • webfetch / bash call hanging.
6. Parent session gives no clear indication of which condition it is.

Environment

• OpenCode: v1.1.36
• OS: Windows (Git Bash/MSYS)
• Model: Claude Sonnet 4.5 Thinking (Antigravity) (as shown in UI)
• Notes: occurs in subagent workflows; parent session lacks visibility.

Related

• Subagents Output in TUI seems strange since 1.1.1 #6880 (subagent output in TUI seems strange)
• Session does not automatically return to parent after subagent execution #6491 (session does not automatically return to parent after subagent execution)
• Opencode Hangs when used as CLI tool #5888 (hangs with no clear way to debug)