Add rule: prefer_frame_over_spacer

[kj6dev]

Overview

Suggest using .frame(maxHeight: .infinity, alignment: .top) instead of VStack { content; Spacer() }

Rule Identifier

prefer_frame_over_spacer

Rationale

More concise, declarative, and performant approach to alignment.

Example

// ❌ Avoid
VStack {
    Text("Header")
    Spacer()
}

// ✅ Prefer
Text("Header")
    .frame(maxHeight: .infinity, alignment: .top)

Notes

This is a preference, not always wrong - VStack+Spacer is more explicit about layout intent. Consider making this a warning rather than error.

Priority

Medium