0.37.0

Added

• Outcome shapes, source format ess/15 (docs/design/outcome-shapes.md): unknown_instance:
  answers an identity no record carries, before an external not-found refusal and wrong_state
  (#145); deletes: removes the subject, and synthesis asserts it is gone from every
  read-your-writes view and that a re-send gets the unknown-instance answer (#151); into: creates
  into a declared state, and generated Rust gets one constructor per creation state (#150);
  accepts: nothing declares an accepted no-op without a subject (#144); system-level
  preconditions: run before every scenario and explorer sequence and must select exactly one
  success branch (#152). Suites using the new steps take ess-conformance/22 and /23; Entity
  Runtime refuses the shapes (OutcomeShapeUnsupported).
• Aggregates over and group keys of Optional fields, source format ess/15 (#148):
  aggregate: {sum: duration, skip_absent: true} skips absent values with SQL semantics, and an
  optional group key makes the absent value its own group. Synthesis arranges one absent row per
  skipping input.
• prefix: on a String newtype (#146), a Json primitive (#138), a field-level
  presence: null_when_absent | omitted_when_absent on Optional fields (#139), and the nested
  naming: {wire: …} spelling on fields (#142), source format ess/15 for the first three.
  Presence is enforced in payload shapes and responses; suites carrying it take
  ess-conformance/24 and /25. Generated Rust, Go, web and CLI targets refuse Json by name,
  as they refuse Binary64. (docs/design/wire-presence-json-prefix.md)
• A field name may start with underscores before its first letter (_url), everywhere a field is
  named, including fact paths and the Go, TypeScript and browser runtimes (#141).
• A map key may be a newtype of an admitted key primitive; it resolves to that primitive while the
  specification, authored scenarios and CLI contracts are read (#143).
• ess verify conform mutate --emit DIR writes each mutant's suite for a project's own runner and
  --collect DIR scores the reports it wrote (#153).
• The Go and TypeScript model explorers take external: branches through the target's external
  control and report reach per branch (#156).
• ess specify toolchain install|list|which: an exact requires: ess X.Y.Z pin makes any ess
  run that release from a verified per-version cache (#147).
• A when_subject predicate may compare a stored field with the command's input,
  recording_id != input.recording_id, source format ess/15 (#157). The finite partition treats
  such a guard as open, so a default is required. Synthesis arranges the row and sends the input
  equal to the stored value for one side and different for the other. Entity Runtime lowers the
  operand to the command's arguments. A stored field named input keeps being read as itself.
• equals_ignore_case (one text literal) and in_ignore_case (a list of them) over String and
  its newtypes, ASCII case folding only, source format ess/15 (#140). Rust, Go and TypeScript
  evaluate them identically; synthesis witnesses the guarded branch with the literal in the other
  case and the default with one character changed. Suites carrying one in a view expectation take
  ess-conformance/20 and /21. Entity Runtime lowering and infra-spec/1 refuse them
  (CaseFoldUnsupported). (docs/design/value-expressions.md E6, E7)

Changed

• Synthesis kills more mutants: a state dropped from an all-states transition gets its refusal
  scenario (#154); any: guards are witnessed once per disjunct and all: once per conjunct,
  over inputs and stored fields (#155); ordering boundaries are witnessed on both sides, including
  .count and near zero (#160); same-typed sources are sent apart and a written value is arranged
  over a different prior value (#161). Committed generated suites are unchanged.
• A wrong-state refusal whose subject no immediate view fully covers is witnessed over the fields
  the declared views publish, with Note::PartialObservation naming what is left out; the refusal's
  help line points at declaring a view (#132).