Update phases.md with Phase 3 checklist (in_progress), add session
progress log entry, record claude CLI architecture decision in
task_plan.md, update README/TODO/CHANGELOG with Phase 3 additions,
and sync .claude/CLAUDE.md with current constraints.
Update progress log with Phase 2 deliverables, mark Phase 2 complete
in TODO/CHANGELOG/README, fix stale Solid.js reference in findings,
update task_plan status to BUILDING, add v2 key paths to CLAUDE.md.