feature: grpc: Host Configuration Validation

[frhuelsz]

🔍 Description

Implement rpc ValidateHostConfiguration

[Copilot]

Pull request overview

This PR implements the ValidateHostConfiguration gRPC endpoint, enabling remote validation of host configuration YAML strings. The implementation adds string-based validation alongside the existing file-based validation, updates the protobuf definitions to return structured error information, and enhances error reporting with separate message and debug fields.

• Adds ValidateHostConfiguration gRPC endpoint implementation
• Refactors configuration parsing to support optional file paths for better error context
• Enhances TridentError proto message with separate message and full_body fields

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
proto/harpoon.proto	Updates ValidateHostConfigurationResponse to use TridentError instead of plain string; adds full_body field to TridentError; formatting cleanup
crates/trident_api/src/error.rs	Adds ParseHostConfiguration error variant; implements From trait for TridentError conversion; separates error message from debug output
crates/trident/src/validation.rs	Refactors parse_host_config to accept optional path; adds validate_host_config_string function for string-based validation
crates/trident/src/server/tridentserver/harpoon_impl.rs	Implements validate_host_configuration endpoint with proper error handling and response construction
crates/trident/src/lib.rs	Updates parse_host_config call to use Some() for path parameter