Implement rux fmt --manifest (TOML Formatter)

[BibhabenduMukherjee]

Feature: Implement rux fmt --manifest (TOML Formatter)

This Pull Request implements the package manifest formatting (rux fmt --manifest) feature, resolving the existing placeholder in the compiler CLI.

Description

The rux fmt --manifest command allows developers to format and standardize their Rux.toml files, ensuring clean formatting, indentation, and key-value alignment. It also supports dry-run checking (--check) to validate if a manifest conforms to standard formatting without writing changes.

Key Features

1. Manifest Formatting: Overwrites Rux.toml with a clean, standardized format (spacing, indentation, section ordering).
2. Formatting Check (--check):
   • Returns exit code 0 if the manifest is already formatted.
   • Returns exit code 1 and prints an error message if formatting discrepancies are found (ideal for CI/CD pipelines).
3. No-Op Safety: Does not perform disk writes if the file is already formatted correctly.

Changes Made

• UtilityCmd.cpp: Implemented the manifestOnly branch in the Cli::RunFmt command to handle manifest loading, temporary serialization comparison, formatting, and verification.

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Verification & Testing

1. Dry Run Verification (--check on unformatted manifest)

$ rux fmt --manifest --check
error: manifest '/path/to/hello_rux/Rux.toml' is not formatted
$ echo $?
1