v0.8.0

opencode joins the farm, and two new team templates come built in: amp-like and gastown-like.

After upgrading, run piggery restart: the daemon then knows opencode and refreshes the built-in
templates you never edited. No existing integration changed, so setup --outdated has nothing to
do. To use opencode, run piggery setup opencode.

• opencode 1.x (tested with 1.18.34): an opencode session you open joins piggery through a plugin,
  and a team can start opencode workers (opencode serve, one per worker). Mail wakes an idle
  session and reaches a busy one at its next step; abort, stop, resume and model work on
  its workers. setup opencode adds one plugin entry to your opencode.json and refuses an
  opencode.jsonc (it prints the line to add by hand). Workers keep your opencode setup, except
  the question and task tools (disabled_tools in harness/opencode.json; a role gets one
  back with spawn.allow_tools).
• Template amp-like, after Amp's oracle and code review: a lead does the
  work and calls an oracle (hard reasoning) or a reviewer (one diff), each answering once. It pays
  off when they run another model family than the lead.
• Template gastown-like, after Gas Town: a mayor splits
  the work, polecats do each task on their own branch and worktree, and a refinery merges the
  branches one at a time into an integration branch. Your own branch moves only when you say.
• council: the chair stops at the verdict and starts agents for other work, such as carrying out
  the decision, only when you ask.
• manifests/README.md draws every built-in template, with when to pick it.
• Forks get an AGENTS.md with the rules that keep the design intact, for people and coding agents.
• setup <harness> keeps one copy of each of your config files it is about to change for the first
  time, in ~/.piggery/backups/setup/<harness>/. setup remove still takes out only piggery's part
  and never restores the copy; it is there if something goes wrong.
• Fix: setup pi --ext then setup remove pi left a settings.json of {} where there was none,
  and could re-indent other values in it (such as packages).