Bump plugin.json 5.7.0 -> 5.8.0, README version badge + version-history row,
and CHANGELOG [5.8.0]. Covers the full Fase 2 campaign motor (durable ledger,
read-only campaign-cli, human-approved campaign-write-cli + /config-audit
campaign, cross-repo backlog, per-repo plan export with execution-by-reuse)
plus the pre-release cleanup (knowledge-refresh wiring, CLAUDE.md trim).
Scanner count 15, agents 7, commands 20 -> 21, tests 1091 -> 1168. All counts
verified green via self-audit --check-readme.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>