Add JqParams and JqResult to expose full jq CLI capabilities and process metadata

[Copilot]

Refactor ExecuteAsync to support JqParams and JqResult

• Create JqParams class with properties for all jq command-line parameters
  • Add properties for: RawOutput, CompactOutput, MonochromeOutput, ColorOutput, Slurp, NullInput, ExitStatus, Args, ArgsJson, etc.
  • Make Query a required constructor parameter (non-nullable)
• Create JqResult class with ExitCode, StandardOutput, and StandardError
  • Add implicit conversion operator to string (returns StandardOutput)
• Create new ExecuteAsync(JqParams params) method that returns Task<JqResult>
• Update existing ExecuteAsync(string json, string query) to use new implementation
  • Construct JqParams internally
  • Call new ExecuteAsync
  • Return StandardOutput for backward compatibility
• Keep all classes in single JQ.cs file
• Add comprehensive tests for new functionality
• Ensure all existing tests continue to pass (13 tests passing)
• Add security validations
  • Validate file existence for SlurpFiles and RawFiles to prevent path traversal
  • Validate that either Json is provided or NullInput is true to prevent hanging
  • Validate Query is not null or empty in constructor
• Fix documentation for JoinOutput and Tab parameters
• Document changes in readme with usage examples

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Add support for all JQ parameters and result exit code, standard output and errors</issue_title>
<issue_description>Refactor the ExecuteAsync so that it receives a JqParams and returns a JqResult.

JqResult should provide the ExitCode, StandardOutput and StandardError from the process for futher inspection. An implicit conversion to string (returning the StandardOutput) should be provided for source compatibility with previous versions.

JqParams should allow providing typed arguments supported by the underlying jq (see docs at https://jqlang.org/).

The existing overload receiving string json, string query should construct the JqParams and invoke the single implementation and return the StandardOutput for backs compat.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add support for all JQ parameters and result exit code, standard output and errors #88

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[kzu]

Make sure you document the changes in the readme

[Copilot]

Make sure you document the changes in the readme

Added documentation for JqParams and JqResult to the readme with usage examples showing both simple and advanced scenarios. See commit 928e499.

The documentation includes:

• Simple usage example (existing API)
• Advanced usage with JqParams and JqResult
• Description of JqResult properties (ExitCode, StandardOutput, StandardError, implicit conversion)
• List of supported JqParams options (output, processing, and variable passing)