v1.2.0

✨ New features

• Nested side agents: side agents can now start their own agents, up to depth 2. A nested agent branches off its parent's branch and merges back into it. Its notifications go only to its parent, and the parent's worktree slot stays pinned while it runs.
• /agent-resume: reopens a side-agent session that was closed with /quit, together with its branch.
  • Uses pi's own session-picker widget, with fast session discovery. Each row shows the agent id and a note saying who owns the branch.
  • Prefers the session's original directory. If the session has to move, it adds a notice about the directory change.
  • Won't reattach branches that active agents own, and restores the session's model.
• Status line as a quick-travel map: nested agents show a parent: entry, then their children, then their siblings, with the groups separated by |. Every entry is colored by status, so from any window you can see which agent needs you next.
• Custom tool rendering: agent-start, agent-check, agent-wait-any and agent-send now show their own compact views in the transcript.
• contrib/tmux-switch: an optional tmux popup that lists windows grouped by project, with side-agent worktrees folded into their repo. Each pi window is colored by state: working, done (not yet looked at) or idle. It's quick to jump between windows by keyboard and there's a live preview. See contrib/tmux-switch/README.md.

🐛 Fixes

• Concurrency and locking
  • Concurrent agent starts now take worktree slots one at a time, so two agents can't grab the same slot.
  • The registry lock is now created atomically with link(2). Only the token holder can release it, stale locks are broken without races, and a live holder is never evicted.
• Worktree reuse: unmerged branches now survive when a slot is recycled.
• Lifecycle notices: notices are merged into one and delivered when the session is idle. They're capped in size, and pending notices are sent on shutdown.
• tmux input
  • agent-send uses bracketed paste, so multiline prompts aren't split, and no longer races with the shell when sending Enter.
  • agent-start sends its commands in a single send-keys. Thanks @tahmed42 (#4).
• Launch wrapper: writes its exit marker more reliably (from an EXIT trap), and transition notices now have timestamps.
• Slug generation: works with reasoning models and spends as little on thinking as possible.

🧪 Tests and docs

• Fixed the integration test harness for pi 0.85.
• Added table-driven status-line tests.
• Added license and package links.

Full changelog: v1.1.3...v1.2.0