feat(transition): complete PRD-to-tasks AI conversion

[LarsCowe]

Problem

convert_prd_with_claude() in task_sources.sh is a stub — it checks for ralph-import but returns 1 immediately. The function was intended to use AI to decompose PRD documents into implementable tasks, but this was never implemented.

The current fallback extract_prd_tasks() is purely syntactic: it finds headings like "TODO" or "Tasks" and extracts bullet items, which misses the intent and priority of requirements.

Proposal

Implement convert_prd_with_claude() using the configured platform driver:

1. Read the PRD file content
2. Invoke the AI with a conversion prompt that asks for markdown checkbox tasks
3. Parse the output and return normalized - [ ] task lines
4. Fall back to extract_prd_tasks() if AI conversion fails

Files

• ralph/lib/task_sources.sh — convert_prd_with_claude() (line 379)

Priority

12/16 — Medium impact, 4 hours effort