feat(providers-tempo): add Tempo RPC provider crate

[shiyasmohd]

Summary

• Add providers-tempo crate with HTTP/WS/IPC transport support, block-streaming client, rate limiting, metrics, and provider configuration
• Add providers-tempo/gen crate for JSON schema generation of Tempo provider config
• Register the Tempo provider in providers-registry so it can be used alongside EVM RPC, Firehose, and Solana providers
• Add gen-tempo-provider-schema justfile recipe and wire it into just gen

TODO: The Tempo Provider crate duplicates some functions from evm-rpc which is intentional for now. That can be deduplicated or simplified in a future PR.

New Crate: providers-tempo

Module	Purpose
client.rs	Block-streaming RPC client with batched and unbatched modes
config.rs	Provider configuration with schemars support
kind.rs	Type-safe "tempo" provider kind identifier
provider.rs	HTTP/WS/IPC transport construction with auth and rate limiting
error.rs	Error types for client and RPC operations
metrics.rs	OpenTelemetry metrics for RPC request tracking

[Theodus]

Found some issues. Should also have Claude review (on GitHub or locally) since there are some minor guideline violations throughout.

[Theodus]

LGTM