Agent Plugins 0.16.0

The ess, aep and worktree plugins describe the newest CLI releases: ess 0.37.0, aep 0.63.1
and worktree 0.8.2. verified.json pins all three.

• aep describes the Git-native store, aep.project/5. The artifact files are the store, a move
  appends to transitions, and each evidence record is one file under .engineering/evidence/.
  aep:planning and aep:implementing read .engineering/project.yaml before the first write, and
  tell the user once, with the exact upgrade, when the store is not /5: /1 migrates with
  aep plan store migrate git --verify, /2–/4 through the pinned build named in
  aep:upgrade. aep:init, adoption and the reverse engineer start new stores at /5. Reasons
  that rested on the old append-only journal now rest on one writer and the revision: conflict.
• ess:hardening uses ess verify conform mutate, with --emit and --collect for a project's
  own runner, and the Go and TypeScript explorers. It no longer says the audit is unshipped. A
  surviving mutant is answered by making the rule observable or filing a synthesis gap, never by
  an authored scenario.
• ess:specifying gains references/later-formats.md: fixtures, value expressions, the outcome
  shapes (unknown_instance:, deletes:, into:, accepts: nothing, preconditions:),
  presence:, Json, prefix:, skip_absent, case-insensitive guards, when_subject_state:
  with its limits, and a per-holder limit ("at most five per member"). Each example validates and
  synthesizes under ess 0.37.0. syntax.md gives the unknown-instance order, instance: on a
  create and on a move, params: on a view, and the one-default rule for outcome whens.
• ess:retrofitting maps a command that ignores in one state and refuses in another. ess:init
  and ess:upgrade cover ess specify toolchain and an exact requires: ess pin.
  ess:testing-conformance covers fixture providers and the suite versions the Go and TypeScript
  runtimes accept.
• The specification interview skips its questions when the request asks for a finished
  specification. Without an AEP store it lists the decisions it took in the report.
• worktree:managing-worktrees covers what archive includes and refuses, and how gc finishes an
  interrupted removal. worktree:init covers activate --install-agent-guidance.
• The ess-pipeline trial fixture sets the fields its invariant reads, which ess 0.37.0 requires
  (ESS-COMMAND-018). The four ESS trials' baselines are re-recorded. ess-new now takes 38 tool
  calls, not 12, because it models the per-member limit it used to leave unmapped; unmapped
  markers fell from 7 to 4.