v1.20.0

Added

• Skill support across the delegation boundary: spawned OpenCode workers now receive plugin
  skills the same way Claude Code injects an agent's frontmatter skills: into its subagents.
  Spawn-time: selected skill digests are baked into the injected oc-delegate agent prompt
  (default: opencode-prompting; oc-reviewer ships none — its report format is fully pinned by
  the contract). Per-call: delegate/fanOut accept skills: string[] (subset of the five
  plugin skills, max 3, deduplicated, validated before any server spawn with SKILL_INVALID /
  SKILL_TOO_MANY); digests are appended to the task prompt under a [PLUGIN SKILLS] marker,
  so guidance also reaches sessions running under the stock build fallback. Selected skills
  are recorded on job records and echoed in tool responses. New module mcp/lib/skills.mjs
  loads SKILL.md bodies (frontmatter stripped, mtime-cached); unreadable skill files degrade
  inline instead of failing the delegation.