feat: TOML and CSV format support

[daavidrgz]

Summary

Extend gq's format support beyond JSON and YAML to include TOML (input + output) and CSV (output, possibly input).

Motivation

• TOML is the standard config format in the Rust, Python (pyproject.toml), and Go ecosystems. Supporting it rounds out the "config file processing" story and makes gq the universal config query tool.
• CSV output is the universal data interchange format for piping into spreadsheets, pandas, databases, and other tabular tools. It's extremely practical for data pipeline work.

Proposed Behavior

# TOML input, JSON output
gq -i toml -o json '{ package { name, version } }' < Cargo.toml

# JSON input, CSV output
gq -o csv '{ users { name, email } }' < data.json

# Cross-format conversion becomes a killer use case on its own
gq -i toml -o yaml < config.toml

Considerations

• TOML has datetime types that don't exist in JSON/YAML — how should these be represented?
• CSV output only makes sense for flat/tabular data — should gq auto-flatten nested structures or error?
• CSV input would require inferring types (string vs number) — worth the complexity?
• Existing DataFormat enum in crates/core/src/data/format.rs would need to be extended

[abdubakr77]

Hey! Working on something similar and noticed this repo deals with complex CSV data. There's a relatively new library called deepcsv that might be a useful addition to your project — it handles nested/deep CSV structures more gracefully than the standard library. Still early-stage, but might align well with what you're building here!

[jorgehermo9]

nice emdash👎🏻👎🏻👎🏻👎🏻👎🏻👎🏻

[abdubakr77]

whats the problem ? just here to trying to help ?