[MarketDataDev03]

Spell out additive vs breaking changes in the review rules

Section 9 of .github/code-review/REVIEW.md defines what breaks this SDK's public surface. Both
the organization's code review bot and the SDK sync pipeline read it to compute the version bump.
Three cases were open to opposite readings, and the same additive API change was computed as a
major bump.

What changes

• The deciding question opens the section: does an existing caller stop compiling, stop
  linking, or see a call that works today against the current API fail or behave differently? If
  not, the change is additive.
• Breaking, added: a change in behaviour that makes a call that works today fail or return
  something different. For example, a default value changed, a field dropped from a response
  model, or a value the API accepts that the SDK now rejects.
• Not breaking, now a list, with three new cases:
  • a new permitted subtype of a sealed interface or class. It is the same case as a new
    enum constant, which this section already treats as not breaking. The new type is listed as
    added, and the sealed parent is not changed;
  • a client-side check on a new method or type;
  • a new client-side check on an existing method that only rejects values the current API
    already rejects. This is not breaking only when the check fails with the error type the API's
    rejection already produces (BadRequestError). Any other type, such as
    IllegalArgumentException, changes the error a working caller handles. That makes it
    breaking, as the sdk rule set says ("the error type a call raises, throws or returns,
    changed").

Only .github/code-review/REVIEW.md changes. The rest of the file, the @include block and the
order are untouched.

Why now

The API change that turned dte into a list, range or comparison is additive for this SDK, and
should be a minor release. The bump was computed as major because of two of these cases:

• new variants of ExpirationFilter;
• an upper bound added to ExpirationFilter.dte(int) that throws IllegalArgumentException.

With these rules:

• the variants are additive;
• a bound on dte(int) stays additive only when it fails with BadRequestError, or when the
  method is left as it was and the API rejects the value.

The review rules apply once this is on main: the bot reads them from the base branch.