Clamp finite frame max width to parent bounds

[caspersimon]

Summary

Fixes Modifier.frame(maxWidth:) on Android so a finite maximum width is clamped by tighter incoming parent constraints, matching SwiftUI behavior.

The max-only branch used Compose requiredWidthIn(max:), which permits the child to measure wider than its parent and then centers the oversized result. This changes only that branch to widthIn(max:). The existing min-only and min-plus-max behavior is unchanged.

Closes #339.

Verification

• Added an Android matrix to the existing testFrameMaxWidthRespectsParentBounds:
  • parent 400, max 680 → 400
  • parent 680, max 680 → 680
  • parent 800, max 680 → 680
  • parent 400, max infinity → 400
• Regression commit reproduced the defect on Android: the first case measured 680 instead of 400.
• With the one-line fix, the same four-case Android test passed (1 test executed).
• swift test --filter LayoutTests.testFrameMaxWidthRespectsParentBounds passed on the host platform (1 test, 0 failures).

Skip Pull Request Checklist:

• REQUIRED: I have signed the Contributor Agreement
• REQUIRED: I have tested my change locally with swift test
• OPTIONAL: I have tested my change on an iOS simulator or device
• OPTIONAL: I have tested my change on an Android emulator or device
• REQUIRED: I have checked whether this change requires a corresponding update in the Skip Fuse UI repository. No Fuse update is required; the defect is isolated to SkipUI's Android modifier mapping.
• OPTIONAL: I have added an example of any UI changes to the Showcase sample app

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• AI was used to generate or assist with generating this PR. AI helped trace the failing modifier branch and draft the regression matrix and PR description. I manually verified the scoped diff, reproduced the regression before applying the fix, reran the identical Android test after the fix, inspected the generated Kotlin, and ran the targeted Swift test.

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