Description:
When I run the following command:

task-master update --from=4 --prompt="Add equipment usage history functionality to equipment management" --research

I get the following error:

[WARN] Expected 22 tasks, but parsed 1.
[ERROR] Parsed task array failed Zod validation.
[ERROR]   - Path '0.status': Required
[ERROR]   - Path '0.dependencies': Required

It seems that the response from Perplexity AI only returns one task and omits required fields like status and dependencies. This causes the task update to fail completely, and no tasks are written back.

Expected behavior:
The tasks from ID 4 and onward should be updated properly, preserving or generating the full structure required (id, status, dependencies, etc.).

Suggestion:
It would be helpful if the task-master could either:

• fallback gracefully when a malformed task is returned
• preserve existing fields (status, dependencies) when not provided by the AI
• or validate AI output before applying, and show a clearer error for resolution