v0.20.0

What's Changed

• feat: abstract VCS layer so agentctl lifecycle works with GitLab by @arun-gupta in #262
• feat: per-project default agent via .agentctl.yml by @arun-gupta in #266
• feat: agentctl open — open worktree in editor or IDE by @arun-gupta in #267
• feat: agent runs tests and reports results in PR before opening by @arun-gupta in #269
• fix: instruct agents to use issue number not full URL in agentctl hints by @arun-gupta in #272
• docs: README diagram, agentctl merge reference, config fields, package list by @arun-gupta in #275
• feat: agentctl build — compile a test binary from an issue worktree by @arun-gupta in #273
• feat: per-run diagnostics — structured metadata for each agent run by @arun-gupta in #274
• fix: diagnostics.List always returns non-nil slice on success by @arun-gupta in #280
• fix: skip non-agentctl worktrees in status and info by @arun-gupta in #283
• fix: finalise diagnostics when headless agent exits by @arun-gupta in #282
• feat: agentctl cleanup accepts multiple issues by @arun-gupta in #286
• fix: agentctl info shows all adapters including those not installed by @arun-gupta in #284
• feat: add agentctl info command for system diagnostics by @arun-gupta in #276

Full Changelog: v0.19.0...v0.20.0