/bar

Generate a bar chart with error bars and grayscale styling for academic publications

## Goal

Generate a publication-ready bar chart with optional error bars, grayscale styling, and Chinese font support.

## Preparation

Collect the following parameters from the user:

| Parameter | Required | Default | Description |
|-----------|----------|---------|-------------|
| `data` | Yes | - | Data source: CSV file path |
| `x` | Yes | - | Column name for categories (X-axis) |
| `y` | Yes | - | Column name for values |
| `error` | No | - | Column name for error values (for error bars) |
| `group` | No | - | Column name for grouping (creates grouped bars) |
| `title` | No | - | Char...