Tabular Column Formatting for MultiSelect Prompt

[TomPlanche]

Problem

When using the MultiSelect prompt to present options with multiple data fields (such as name, size, date, and path), the current display can be difficult to read because columns aren't aligned. This makes it hard to scan and compare values across options.

Current Display

Select projects to clean:
> [x] copy_current_location: 898.95 KB (2025-10-12 15:41) /Users/tom_planche/Prog/Rust/copy_current_location
  [x] summary-gen: 211.29 MB (2025-10-13 20:04) /Users/tom_planche/Prog/Rust/summary-gen
  [x] rona: 1.26 GB (2025-10-14 18:29) /Users/tom_planche/Prog/Rust/rona/rona
  [x] src-tauri: 2.59 GB (2025-10-13 10:24) /Users/tom_planche/Prog/Rust/wordle-helper/src-tauri
  [x] clean-dev-dirs: 2.75 GB (2025-10-15 11:50) /Users/tom_planche/Prog/Rust/clean-dev-dirs

In this format, it's difficult to:

• Quickly compare file sizes across projects
• Scan dates chronologically
• Identify patterns in the data

Proposed Solution

Add support for tabular column formatting that automatically aligns columns, making structured data much easier to read.

Desired Display

Select projects to clean:
> [x] copy_current_location 898.95 KB (2025-10-12 15:41) /Users/tom_planche/Prog/Rust/copy_current_location
  [x] summary-gen           211.29 MB (2025-10-13 20:04) /Users/tom_planche/Prog/Rust/summary-gen
  [x] rona                  1.26 GB   (2025-10-14 18:29) /Users/tom_planche/Prog/Rust/rona/rona
  [x] src-tauri             2.59 GB   (2025-10-13 10:24) /Users/tom_planche/Prog/Rust/wordle-helper/src-tauri
  [x] clean-dev-dirs        2.75 GB   (2025-10-15 11:50) /Users/tom_planche/Prog/Rust/clean-dev-dirs
  [x] qobuz-client          3.21 GB   (2025-10-12 16:52) /Users/tom_planche/Prog/Rust/qobuz-client

With aligned columns:

• Project names line up on the left
• File sizes align (can be right-aligned for numerical comparison)
• Dates are vertically aligned
• Paths start at the same horizontal position

Use Cases

This feature would be particularly valuable for:

1. File and Directory Browsers

   • Displaying files with size, modification date, and permissions
   • Project selectors showing metadata

2. System Monitoring Tools

   • Process lists with PID, memory usage, CPU usage
   • Service status displays

3. Package Managers

   • Package lists with name, version, size, and description
   • Dependency trees with metadata

4. Build Tools

   • Target selection with build time, size, and status
   • Test results with name, duration, and status

5. Database/Data Tools

   • Record selection with multiple fields
   • Query result browsing

Requirements

• Automatic column width calculation: Columns should automatically size based on the widest content
• Alignment options: Support for left-aligned and right-aligned columns (numbers benefit from right-alignment)
• Unicode support: Must handle unicode characters correctly when calculating widths
• Works with filtering: When users type to filter options, columns should re-align based on visible options only
• Backward compatible: This should be an opt-in feature that doesn't affect existing usage
• Column separator definition: Users should be able to specify what character sequences separate columns in their data

Benefits

1. Improved Readability: Structured data is significantly easier to scan and understand
2. Better User Experience: Users can make more informed decisions when comparing options
3. Professional Appearance: Aligned columns look more polished and intentional
4. Accessibility: Consistent spacing helps users with visual processing differences