fix: 🐛 Improve command help and option diagnostics - #82

Problem

Redirected help could contain ANSI escapes, every command shared one large option list, and argument errors omitted the option a user needed to correct.

Refs #65

Changes

• Disable help colors when the JVM has no terminal console or NO_COLOR is present, including an empty value. This overrides forced Picocli colors for redirected output.
• Show required and accepted options, combination notes and an example for each command. Root and command-family help list commands; inspect --help also exposes its offline subcommands.
• Reuse command-guide option sets for the strict combinations already validated by the interpreter. Execution parsing and existing general-command validation remain intact.
• Name unknown options and invalid/missing option values in JSON errors. Strip attached values and avoid echoing parser exception messages. Preserve error schemas, codes and exit statuses.
• Add command-help examples to both quickstarts and describe output behavior in the CLI contract. No CLI flags or dependencies are added.

Validation

• Full Linux tests, coverage and release-input checks passed: XML reports 249 tests, zero failures/errors/skips; one entry represents an empty Windows-only specification. Line coverage 95.35%, branch coverage 80.45%, against unchanged 90%/80% floors.
• Native Windows JDK 21: all 15 CLI usability regressions passed, including real ConPTY output and an empty NO_COLOR value.
• Packaged CLI: 52 Linux scenarios covering all 21 command help pages, command families, redirected and terminal output, safe diagnostics, version output and the command launcher. Native Windows batch launcher also passed redirected command-specific help checks without ANSI or stderr.
• The exact final test classes fail 13 cases against the prior JAR; the two passing controls verify permitted colored terminal output and safe positional-error fallback.

Examples and message wording remain human-readable help, not a machine-readable API. Scripts should continue to use versioned JSON envelopes and error codes for command execution.