SnapshotFormat

The canonical text codec for a Snapshot — the deterministic, human-readable, diffable artifact (BCV's lesson: a sorted golden text reviewers can read).

Guarantees:

• Deterministic / byte-stable: the same snapshot always serializes to the same bytes; everything is emitted in sorted order with no environment input.

• Order-invariant: because the Snapshot model normalizes its collections, reordering fields, enum values, or subtypes produces identical text.

• Round-trips: parse(serialize(s)) == s for every extractor-produced snapshot; list values (jsonNames, enum values) escape whitespace and the comma separator, so they survive tokenization like any other token (#146).

Format (lists are comma-separated with no spaces; type refs contain no spaces):

@contract com.example.OrderEvent kind=CLASS
  amountCents: Long
  note: String optional
  tags: List<String> optional jsonNames=[labels]

@contract com.example.OrderStatus kind=ENUM
  values=[CANCELLED,CREATED,PAID]

@contract com.example.Payment kind=SEALED discriminator=type
  subtypes:
    ach -> com.example.AchPayment
    card -> com.example.CardPayment

@config
  classDiscriminator=type
  ...