fix(taskctl): resurrectionScan resets developing tasks to idle instead of advancing to reviewing

[randomm]

Problem

When the opencode binary restarts, resurrectionScan runs on taskctl resume. For tasks with stage: developing where the developer session is no longer alive, resurrection resets them to status: open, stage: idle, assignee: null and removes the worktree.

This destroys completed developer work. A developer that finished before the binary restarted loses all its changes.

Root Cause

resurrectionScan conflates two scenarios:

1. Crash mid-development: session died unexpectedly → correct to reset and retry
2. Completed before restart: session finished normally, binary restarted before heartbeat advanced stage → wrong to reset

Both look identical to resurrection: stage: developing + dead session.

Fix

In resurrectionScan, check pipeline.last_activity timestamp. If the session is dead AND the task is in stage: developing, advance to stage: reviewing instead of resetting to idle. Preserve the worktree and branch.

Alternatively: before resetting, check if the worktree has uncommitted changes. If it does, treat as completed and advance to reviewing.

Acceptance Criteria

• Developer work is preserved across binary restarts
• Task advances to reviewing when developer session is dead after restart
• Worktree is NOT removed when advancing to reviewing
• Crash scenario (mid-development) still correctly resets to idle
• bun test and bun run typecheck pass