Summary

This PR adds MessagePack binary serialization support to ZIO Blocks, porting the functionality from zio-schema-msgpack to the new ZIO Schema 2 architecture.

Changes

• New module: schema-messagepack

  • MessagePackBinaryCodec[A] - Abstract class extending BinaryCodec[A] for MessagePack encoding/decoding
  • MessagePackFormat - Binary format with Deriver[MessagePackBinaryCodec] for automatic codec derivation

• Supported types:

  • All primitive types (Unit, Boolean, Byte, Short, Int, Long, Float, Double, Char, String)
  • Numeric types (BigInt, BigDecimal)
  • Date/Time types (Instant, LocalDate, LocalDateTime, LocalTime, Duration, Period, etc.)
  • UUID, Currency
  • Records (case classes) - encoded as MessagePack maps
  • Variants (sealed traits) - encoded with _type discriminator field
  • Sequences (List, Vector, etc.) - encoded as MessagePack arrays
  • Maps - encoded as MessagePack maps
  • Wrapper types
  • DynamicValue

• Dependencies:

  • org.msgpack:msgpack-core:0.9.8

Example Usage

import zio.blocks.schema._
import zio.blocks.schema.messagepack.MessagePackFormat

case class Person(name: String, age: Int)
implicit val schema: Schema[Person] = Schema.derived
val codec = schema.derive(MessagePackFormat.deriver)

val person = Person("Alice", 30)
val bytes = codec.encode(person)
val decoded = codec.decode(bytes) // Right(Person("Alice", 30))

Test Plan

• Round-trip tests for all primitive types
• Round-trip tests for records (simple, nested, with optional fields)
• Round-trip tests for variants (sealed traits)
• Round-trip tests for sequences (List, Vector)
• Round-trip tests for maps
• CI checks pass

Related Issues

/claim #682

Closes #682