Add unit tests for utility functions in cmd/status/view_test.go:
- formatRate: MB/s rate formatting with adaptive precision
- shorten: string truncation with ellipsis
- humanBytesShort: byte formatting with binary units
Add unit tests for heap implementations in cmd/analyze/heap_test.go:
- entryHeap: min-heap for dirEntry (basic ops, empty, single element)
- largeFileHeap: min-heap for fileEntry (basic ops, top N pattern)
