• Changing a schedule's action now drops fires buffered under the old
  action (#876). Each dropped fire is recorded as a ScheduleTriggerSkipped
  event with reason action_changed and its occurrence_time. Updates that
  leave the action unchanged keep the buffer.
• Memo and search attribute limits now apply the same way on start, embedded
  upserts and worker upserts (#853). Going over a fixed cap (memo value
  10,240 bytes, 100 memo keys, 65,536 memo bytes, search attribute string
  2,048 or keyword 255 characters, 100 attributes, 65,536 attribute bytes)
  raises StructuralLimitExceededException instead of
  InvalidArgumentException. Its new limitName says which limit was hit,
  and a failed run records it as structural_limit_name. An embedded upsert
  over a fixed cap now fails the run as a non-retryable structural-limit
  failure, as the configured limits already did.
• Start now applies the configured memo_size_bytes and
  search_attribute_size_bytes limits. A configured limit can tighten a
  fixed total but no longer appears to raise it. The memo_size_bytes
  default is now 65,536 (was 262,144, which the fixed 64 KiB total made
  unreachable). Zero still turns the configured limit off; the fixed caps
  stay. Upgrade note: code that caught InvalidArgumentException for these
  limits should catch StructuralLimitExceededException.