Plans live inline in tasks, not in doc/plans

Design and implementation plans live inline in the task that owns the work: the working strategy/analysis goes in the task's * Plan (and * Notes for supporting material), and the durable outcomes distil into the parent story's * Decisions. Do not create a separate plan file under doc/plans/ for live work.

Why: The v2 information architecture treats a task's * Plan as transient — written when work starts, distilled into the story's * Decisions, and cleared when the task closes ("plans do not outlive their task"). doc/plans/ is the historical archive of older one-off plans, not where current design belongs. The user corrected a design task that proposed writing its taxonomy to doc/plans/YYYY-MM-DD-*.org.

How to apply: When scaffolding or writing a design/analysis task (taxonomies, migration strategies, architecture decisions), put the analysis and the working tables in the task body and the settled choices in the story's * Decisions. Only reference doc/plans/ to read historical plans; never direct new live design output there. Earlier docs (e.g. the compass CLI UX taxonomy) used doc/plans/ — follow their content shape, not their location.