Function formatByteSize

formatByteSize(
bytes: number,
opts?: { decimals?: number; unit?: "kb" | "mb" | "gb" | "tb" },
): string
Formats a byte value into a human-readable string.

WHY: Converts raw byte values into user-friendly strings for display. Automatically selects the most appropriate unit (KB, MB, GB, TB).
Parameters
- bytes: number
  number of bytes to format
- opts: { decimals?: number; unit?: "kb" | "mb" | "gb" | "tb" } = {}
  optional formatting options
  - Optionaldecimals?: number
    number of decimal places (default: 2)
  - Optionalunit?: "kb" | "mb" | "gb" | "tb"
    force a specific unit instead of auto-selecting
Returns string
formatted string (e.g., "10.5mb", "2gb")
Example
```
formatByteSize(1024);              // "1kb"
formatByteSize(1536);              // "1.5kb"
formatByteSize(10485760);          // "10mb"
formatByteSize(1073741824);        // "1gb"
formatByteSize(1536, { decimals: 0 });  // "2kb"
```
Example
```
// Force specific unit
formatByteSize(1024, { unit: 'mb' });  // "0mb"
formatByteSize(1024, { unit: 'kb' });  // "1kb"
```
Example
```
// Display file sizes
files.forEach(file => {
    console.log(`${file.name}: ${formatByteSize(file.size)}`);
});
```
- Defined in packages/utils/src/units/bytes.ts:169