refactor(ui): InsetHeaderScrollView, shared tab swipes

[pwltr]

Description

• add a reusable InsetHeaderScrollView with measured top safeAreaInset header + scroll content minHeight to fill the viewport below. To be used on scrollable screens with headers like AllActivity, MainSettings, ShopDiscover.
• add swipeSegmentedTabs for AllActivity, MainSettings, and ShopDiscover segmented controls (horizontal swipe to change tabs).
• refactor Card views
• fix "lightbulb" figure image

Screenshot / Video

Simulator.Screen.Recording.-.iPhone.17.-.2026-05-04.at.23.44.27.mov

QA Notes

Make sure changed screens look polished and suggestion/shop cards still work as expected.

[chatgpt-codex-connector]

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[claude]

Bug: contentMinHeight fallback returns 0 instead of the full viewport height

The conditional is inverted. When headerHeight == 0 (before the first preference propagation), insetTop is set to geo.size.height, so the method returns max(0, geo.size.height - geo.size.height) = 0. This contradicts the doc comment — "use full height so minHeight is non-negative" — and causes scroll content to collapse to zero minimum height on first render, producing a visible layout flash. SupportScreen, which previously used geometry.size.height for frame(minHeight:) to pin footer content at the bottom, will regress.

Context:

bitkit-ios/Bitkit/Components/InsetHeaderScrollView.swift

Lines 59 to 63 in 09fe376

	/// Before the first header measurement, use full height so `minHeight` is non-negative.
	private func contentMinHeight(in geo: GeometryProxy) -> CGFloat {
	let insetTop = headerHeight > 0 ? headerHeight : geo.size.height
	return max(0, geo.size.height - insetTop)
	}

The fix is to swap the fallback: when headerHeight is not yet known, subtract 0 so the content gets the full geometry height as its minimum.

Suggested change

	let insetTop = headerHeight > 0 ? headerHeight : geo.size.height
	let insetTop = headerHeight > 0 ? headerHeight : 0

[claude]

CLAUDE.md: name Card violates the descriptive-names rule

CLAUDE.md states:

Use descriptive names (e.g., UserProfileCard not Card)

Card is the exact anti-example cited in the rule. The doc comment already describes a specific semantic role ("Shared gradient tile used by suggestions widget and shop discover"), so a more descriptive name is straightforward — e.g. SuggestionTileCard or GradientTileCard.

Context:

bitkit-ios/Bitkit/Components/Card.swift

Lines 3 to 5 in 09fe376

	/// Shared gradient tile used by suggestions widget and shop discover
	struct Card: View {
	let title: String