chore(okr): bump 1.6.0 (OKF second brain) + CLAUDE.md/README/CHANGELOG docs
Bump 1.5.0 -> 1.6.0 across plugin.json, CLAUDE.md title, okr-offentlig-sektor SKILL.md, README badge. README version-history row + Under-the-Hood Skills table; CHANGELOG 1.6.0 entry. CLAUDE.md gains OKF Knowledge Layout section (two-root model, okf-index/okf-check/compose-org-profile, lib/frontmatter), second skill in Skills table, and two architecture lines.
Ref-count: kept '16 domain reference files' (correct -- freshen-references scores 16, excludes okr-quality-rubrics.md as the scoring instrument; 17 is the directory total). Tightened CLAUDE.md:20 wording to '16 domain' for clarity; did NOT apply the plan's 16->17 (would contradict the command). References dir untouched (SC9). Verify: node --test 55/55; all version surfaces 1.6.0.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SFW5scLL7oEwWWTv1fPQG6
Kjell Tore Guttormsen
7fdbf9bcbd