[CLI]: add RPC Adapter with Inspect Diamond command - #375

Summary

Add an RPC adapter layer to the CLI and two new commands: rpc for connection testing and inspect for querying Diamond proxy state (facets, selectors, function signatures). The RPC URL is resolved from compose.json chain definitions with environment variable interpolation support.

Changes Made

RPC Adapter (cli/src/adapters/rpc/)

• IRPCAdapter interface: readContract and getCode methods backed by viem
• createRPCAdapter factory: builds a viem public client with configurable retry policy (2 retries, 50ms/200ms backoff), transient-error classification, and Retry-After header support
• Validation: rejects invalid URLs, non-HTTP(S) protocols, non-positive chain IDs
• Error hierarchy: RPCError with stable codes (RPC_INVALID_CONFIGURATION, RPC_REQUEST_FAILED, RPC_UNAUTHORIZED, etc.)

rpc Command

• Tests RPC connectivity for a given chain (defaults to local)
• Optionally verifies a contract address has deployed bytecode
• Resolves chain config from compose.json via the dependency resolver

inspect Command

• Queries a deployed Diamond address for all facets, selectors, and function signatures via DiamondLoupe
• Decodes selectors against common ERC/Diamond signatures and project ABI files
• Supports both Foundry and Hardhat artifact directories (auto-detected or overridden)
• Outputs facet tree with decoded function signatures

Infrastructure

• chainConfig.ts: resolves chain RPC URLs from compose.json with ${ENV_VAR} interpolation
• loadEnvFiles(): hierarchical .env loading from cwd up to filesystem root
• Dependency resolver: new DependencyKey.RPC with factory that creates adapters on demand
• Pipelines: thin rpcPipeline and inspectPipeline orchestrations

Tests

• RPC adapter: chain ID verification, retry on transient failures (503), Retry-After header, non-retryable errors (401), bytecode verification
• Inspect module: ABI loading (Foundry/Hardhat), selector decoding, invalid address handling, missing contract code
• Commander: command registration, positional args, flag defaults
• Chain config: env var interpolation, missing vars, invalid keys

Checklist

Before submitting this PR, please ensure:

• Code follows the Solidity feature ban - No inheritance, constructors, modifiers, public/private variables, external library functions, using for directives, or selfdestruct

• Code follows Design Principles - Readable, uses diamond storage, favors composition over inheritance

• Code matches the codebase style - Consistent formatting, documentation, and patterns (e.g. ERC20Facet.sol)

• Code is formatted with forge fmt

• Existing tests pass - Run tests to be sure existing tests pass.

• New tests are optional - If you don't provide tests for new functionality or changes then please create a new issue so this can be assigned to someone.

• All tests pass - Run forge test and ensure everything works

• Documentation updated - If applicable, update relevant documentation

• Changesets — If this PR changes publishable packages (src/, cli/), changeset-bot will comment if a release note might be needed. You can add one when convenient or defer to maintainers.

Make sure to follow the contributing guidelines.

Additional Notes