Clicking on subagent labels in TUI does not navigate to subagent session

[altendky]

Description

After commit c5442d4 ("refactor(session): effectify SessionPrompt service"), clicking on subagent labels in the TUI no longer navigates to the subagent session view. Clicking does nothing.

The TUI click handler checks props.metadata.sessionId and only navigates if it's truthy. The sessionId is set via ctx.metadata() during task tool execution, but this metadata is being silently dropped due to a race condition in the new queue-based LLM layer.

Plugins

None

OpenCode version

dev branch, after c5442d4

Steps to reproduce

1. Start opencode TUI
2. Prompt: "launch 3 subagents each sleeping for 60 seconds"
3. While subagents are running, click on any subagent label
4. Expected: navigate to subagent session view
5. Actual: nothing happens

Screenshot and/or share link

N/A

Operating System

Linux (reproduced on Ubuntu)

Terminal

Ghostty

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Bisect result: Regression introduced by c5442d4

[github-actions]

This issue might be a duplicate of or closely related to existing issues. Please check:

• Clicking on Task tool no longer navigates to subagent session #15769: "Clicking on Task tool no longer navigates to subagent session" (CLOSED) — same symptom, previously fixed via a different root cause (BlockTool→InlineTool refactor). Your issue may represent a regression of the same UX after a subsequent refactor.
• bug(tui): subagent navigation broken for nested sessions and imprecise for multiple concurrent tasks #15972: "bug(tui): subagent navigation broken for nested sessions and imprecise for multiple concurrent tasks" (OPEN) — overlapping symptom (click-to-navigate broken), though it covers additional UX issues around nested sessions and concurrent tasks.

If the fix from #15769 was inadvertently reverted or broken by c5442d418, it may be worth referencing those issues for context.

[rmk40]

Opened #20187 as a fix. The root cause is that ctx.metadata() fires while the part is still pending, and the processor's tool-call handler overwrites it with a fresh state. Fix uses a synchronous side-channel on the processor context to buffer metadata until the tool-call handler can merge it.

[rmk40]

Fix + E2E regression test: #20198 (supersedes #20187)