Generate a commit message for these changes:

File changes:
{changes}

Diff:
{diff_content}

Format:
<type>(<scope>): <subject>

<body>

Important:
- Type must be one of: feat, fix, docs, style, refactor, perf, test, chore
- Subject line should be 50-70 characters
- Use imperative mood in subject line
- Do not end subject line with period
- Body should explain what and why, not how
- For minor changes, use fix instead of feat

Response should be the commit message only, no explanations. 