feat(components): add SegmentDensity (Regular/Compact) to SegmentedContent

[maniramezan]

Adds a density preset to SegmentedContent, mirroring SegmentDensity added to SwiftUIComponents' SegmentedPicker (iOS/Android parity).

What

enum class SegmentDensity { Regular, Compact }
SegmentedContent(items = …, density = SegmentDensity.Compact, …)

• Regular (default) — unchanged: 48dp minimum touch target.
• Compact — segment height floor drops to ~32dp (spacing.x4) and the title's vertical padding halves, matching a native compact segmented control.

Threaded through both public overloads → SegmentBar → even/intrinsic/scrollable rows → SegmentSlot. New param defaults to Regular, so existing callers are unaffected (source-compatible).

Showcase & sample

• New SegmentedContentCompactPreview (@PreviewLightDark) + matching Showkase entry.
• Sample app's SegmentedContent page gains a Density control (Regular/Compact) so it's demonstrated in the catalog/sample.

Tradeoff (documented on the enum)

At Compact the tap target shrinks with the control (below the 48dp guideline) — use where a tighter control matters more than a generous tap area.

Verification

:components and :sample compile, ktlint, detekt all pass; :catalog:assembleDebug succeeds; :components:testDebugUnitTest passes.

Follow-up (after release)

Bump the Android app's composeUiLib and set density = SegmentDensity.Compact on the video-details segview header (parity with the iOS change already on main).