v2.8.0

Breaking changes, in a minor

Two types stop accepting code they used to accept. Both reject only code
that was already wrong when it ran — see the exception recorded in
docs/RELEASING.md, which requires this heading and the
argument below.

• parse() returns the type your transforms leave behind. It applies
  them, so it always did return the transformed value; the type said
  otherwise:

  .v("when", (b) => b.string.required().transform((s) => new Date(s)))
  
  parsed.data.when.toUpperCase()   // compiled. threw.

  What breaks: code reading a transformed field as its declared type.
  That code was throwing. validate() is unchanged — it applies no
  transform, so its type was right and stays right.

  Nested paths and items[*].field both rewrite. A field declared through
  useField() does not participate: a field rule stores its chain as
  AnyChain, so the type is erased before it can be recorded.

• A check written after a transform no longer compiles. The runtime
  order is fixed and is not the written order — every check runs before
  every transform:

  b.string
    .required()
    .transform((s) => `${s}!`)
    .min(3);

  reads as "append, then require three characters". With "ab" the min
  fails, the transform never runs, and the field is invalid.

  What breaks: any chain with a check after a transform. It was doing
  the opposite of what it read. Move the check above the transform, or
  transform first and check the new value in its own field. The refusal
  says so: CheckAfterTransform carries the method name and the fix,
  rather than "Property 'min' does not exist", which is what a forgotten
  import says too.

Changed

• A field runs the stages it declared, and no others. One that declared
  only presence and checks was reaching them through five stages with
  nothing to do. Measured A/B, four rounds alternating: 221.0 / 192.3 /
  211.2 / 177.6 ns before, 152.5 / 163.0 / 139.0 / 144.4 ns after, no round
  overlapping. Allocation per validate() of one string field went 144.6
  to 8.5 bytes.

Fixed

• An issue raised inside an array element could be lost. forArrayElements()
  shares the parent's issue buffer by reference, and the buffer is built
  lazily now — sharing it before it exists shared nothing.

Repository

• Competitors are measured twice, once with run-time code generation
  allowed and once with it forbidden, because a strict Content-Security-
  Policy makes them different programs. zod compiles a per-shape validator
  through new Function when it can and interprets when it cannot; ajv
  does not degrade at all — compile() throws and there is no validator.
• The version policy gained one narrow exception, with the burden of proof
  written into it.