fix: Gist URL capture and human-readable file size display

[konard]

Summary

• Fix gist URL not being captured: The gh gist create command was failing to capture the URL due to empty string interpolation issues in the command-stream template literal when creating private gists
• Add human-readable file size display: Added formatFileSize() function that properly formats file sizes (e.g., "1.90 KB" instead of "0.00 MB" for small files)
• Improve CLI output: Enhanced user experience with better formatting and file info display before upload starts

Root Cause Analysis

The issue was in src/index.js line 211-213:

const visibility = isPublic ? '--public' : '';
const result = await $`gh gist create ${filePath} ${visibility} --desc ${desc}`;

When visibility was an empty string for private gists, the command-stream template literal interpreted this incorrectly, causing a shell pattern matching error (no matches found for \``) and losing the gist URL from stdout.

Solution

Changed to use conditional command execution:

let result;
if (isPublic) {
  result = await $`gh gist create ${filePath} --public --desc ${desc}`;
} else {
  result = await $`gh gist create ${filePath} --desc ${desc}`;
}

Changes Made

• src/index.js: Fixed gist upload command, added formatFileSize() function
• src/cli.js: Improved CLI output with file info before upload
• test/index.test.js: Added 7 new tests for formatFileSize function
• experiments/: Added experiment scripts documenting the issue and solution

Test plan

• Unit tests pass locally (37 tests)
• End-to-end test confirms gist URL is captured correctly
• File size now displays correctly (e.g., "1.90 KB" for a 1.9KB file)
• Lint and format checks pass

Fixes #13

🤖 Generated with Claude Code

[konard]

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