[Bug] Task tool shows no visual feedback - sessionId not available at tool_start

[randomm]

Problem

When PM dispatches a task to a subagent, the UX is broken:

1. No visual feedback during task — User sees blank screen for 10+ seconds, then static text for minutes
2. No subagent tool output — Child session's tools don't render
3. Task completion doesn't auto-wake PM — User has to manually prompt ("any luck?") to see results

Root Cause

Issue 1 & 2: sessionId timing

In task.ts, ctx.metadata({ sessionId }) is called AFTER session creation (line 222-228).
But in index.ts, we look for chunk.metadata?.sessionId during tool_start.
The tool_start event fires BEFORE ctx.metadata() is called, so sessionId is undefined.

Issue 3: Auto-wakeup not triggering UI update

Session.enableAutoWakeup() is called (line 317 in task.ts), but the CLI doesn't seem to respond to it.

Timeline

tool_start fires → metadata.sessionId = undefined → taskToChildSession not set
   ↓
ctx.metadata() called → sessionId now available → but we don't update the map
   ↓
child session tools fire → taskToChildSession lookup fails → tools not rendered
   ↓
task completes → auto-wakeup triggered → CLI doesn't update display
   ↓
user has to type "any luck?" to see results

Requirements

• Task dispatch shows immediately (agent name, description)
• Child session tools render nested under the task
• Task completion auto-updates the display (no manual prompt needed)
• No 10+ second blank screen

Files

• packages/opencode/src/tool/task.ts — Where metadata is set
• packages/opencode/src/cli/lite/index.ts — Where we try to read it
• packages/opencode/src/cli/lite/liveblock.ts — Task rendering

[randomm]

Fixed in d6f0886 - Task shows immediately, auto-wakeup enabled, child session linking via Bus