feature: v2 config amqp, grpc interceptors

[rustatian]

Summary by CodeRabbit

• Documentation
  • Introduces versioned, nested AMQP pipeline configuration (recommended v2) with separate exchange/queue settings, plus v0/v1 legacy compatibility, v3 examples, migration guidance, and read-only RabbitMQ deployment examples.
  • Clarifies producer-only rules, validation/Nack/startup behavior, runtime/RPC notes, and adds navigation "What’s Next" guidance.
  • Adds gRPC interceptors documentation and a cross-reference in the gRPC guide (SUMMARY updated).