Update CLAUDE.md and NOTEBOOK.md to reflect current state

CLAUDE.md: Rectified from outdated "prototype" description to
accurate summary of the working 0.9.0-beta plugin. Updated
technology versions, feature inventory, extension points,
RIDDL API usage (RiddlLib), project structure, and test status.

NOTEBOOK.md: Graduated completed phase plans and codebase
assessment. Consolidated session logs. Added Changes Since
0.9.0-beta section for version tracking. Focused on actionable
next steps (marketplace, coverage, find usages, legacy cleanup).
Reduced from 1025 to 224 lines.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: respencer-ncl