Tasks created via TaskCreate are lost during conversation compaction

Description

When a conversation is compacted (either manually via /compact or automatically at context limits), all tasks created via TaskCreate / TaskUpdate are permanently lost. There is no mechanism to persist or restore them.

Steps to Reproduce

1. Start a Claude Code conversation
2. Create multiple tasks using TaskCreate (e.g., 20+ tasks for a complex project)
3. Work through tasks, updating status with TaskUpdate
4. Trigger compaction (/compact or reach context limit)
5. Run TaskList after compaction

Expected Behavior

Tasks should survive compaction, or at minimum:

• Tasks should be included in the compaction summary
• Or tasks should be persisted to a file before compaction
• Or the task system should use file-backed storage instead of in-memory only

Actual Behavior

TaskList returns "No tasks found" after compaction. All task state (subjects, descriptions, statuses, dependencies) is completely lost with no way to recover.

Impact

For complex multi-step projects (in this case, 20+ design tasks across 12 modules), losing the task list means:

• No record of what was completed vs pending
• No record of task dependencies
• User must manually reconstruct the entire task list from conversation memory
• Risk of duplicated or missed work

Environment

• Claude Code CLI
• Model: claude-opus-4-6 (1M context)
• macOS Darwin 24.6.0

Suggested Fix

Either:

1. Persist tasks to a file (e.g., .claude/tasks.json) so they survive compaction
2. Include task state in compaction summary so they can be auto-reconstructed
3. Warn before compaction if there are active tasks, giving the agent a chance to persist them

Workaround

Manually maintain a TODO.md file in the project directory mirroring all task state. This is what I'm now doing, but it defeats the purpose of the built-in task tools.