add ViewModeToggle component with element theming and neutral mode

src/lib/components/ui/ViewModeToggle.svelte

@@ -0,0 +1,152 @@
+<svelte:options runes={true} />
+
+<script lang="ts">
+	import Icon from '../Icon.svelte'
+	import Tooltip from './Tooltip.svelte'
+	import type { ViewMode } from '$lib/stores/viewMode.svelte'
+
+	interface Props {
+		/** Current view mode */
+		value?: ViewMode
+		/** Callback when view mode changes */
+		onValueChange?: (mode: ViewMode) => void
+		/** Element color theme for active state */
+		element?: string
+		/** Use neutral gray styling instead of element colors */
+		neutral?: boolean
+		/** Additional class name */
+		class?: string
+	}
+
+	let { value = 'grid', onValueChange, element, neutral = false, class: className }: Props = $props()
+
+	function handleModeChange(mode: ViewMode) {
+		onValueChange?.(mode)
+	}
+
+	const containerClass = $derived(
+		['view-mode-toggle', neutral ? 'neutral' : element, className].filter(Boolean).join(' ')
+	)
+</script>
+
+<div class={containerClass} role="group" aria-label="View mode">
+	<Tooltip content="Grid view">
+		<button
+			type="button"
+			class="toggle-btn"
+			class:active={value === 'grid'}
+			onclick={() => handleModeChange('grid')}
+			aria-label="Grid view"
+			aria-pressed={value === 'grid'}
+		>
+			<Icon name="grid" size={18} />
+		</button>
+	</Tooltip>
+	<Tooltip content="List view">
+		<button
+			type="button"
+			class="toggle-btn"
+			class:active={value === 'list'}
+			onclick={() => handleModeChange('list')}
+			aria-label="List view"
+			aria-pressed={value === 'list'}
+		>
+			<Icon name="list" size={18} />
+		</button>
+	</Tooltip>
+</div>
+
+<style lang="scss">
+	@use '$src/themes/spacing' as *;
+	@use '$src/themes/layout' as *;
+	@use '$src/themes/effects' as *;
+	@use '$src/themes/colors' as *;
+
+	.view-mode-toggle {
+		display: flex;
+		gap: $unit-fourth;
+		padding: $unit-fourth;
+		background: var(--segmented-control-bg);
+		border-radius: $item-corner;
+
+		// Default colors (null element)
+		--toggle-active-bg: var(--null-button-bg);
+		--toggle-active-bg-hover: var(--null-button-bg-hover);
+		--toggle-active-icon: white;
+
+		// Element-specific colors
+		&.wind {
+			--toggle-active-bg: var(--wind-button-bg);
+			--toggle-active-bg-hover: var(--wind-button-bg-hover);
+			--toggle-active-icon: var(--wind-text-contrast);
+		}
+
+		&.fire {
+			--toggle-active-bg: var(--fire-button-bg);
+			--toggle-active-bg-hover: var(--fire-button-bg-hover);
+			--toggle-active-icon: var(--fire-text-contrast);
+		}
+
+		&.water {
+			--toggle-active-bg: var(--water-button-bg);
+			--toggle-active-bg-hover: var(--water-button-bg-hover);
+			--toggle-active-icon: var(--water-text-contrast);
+		}
+
+		&.earth {
+			--toggle-active-bg: var(--earth-button-bg);
+			--toggle-active-bg-hover: var(--earth-button-bg-hover);
+			--toggle-active-icon: var(--earth-text-contrast);
+		}
+
+		&.dark {
+			--toggle-active-bg: var(--dark-button-bg);
+			--toggle-active-bg-hover: var(--dark-button-bg-hover);
+			--toggle-active-icon: var(--dark-text-contrast);
+		}
+
+		&.light {
+			--toggle-active-bg: var(--light-button-bg);
+			--toggle-active-bg-hover: var(--light-button-bg-hover);
+			--toggle-active-icon: var(--light-text-contrast);
+		}
+
+		// Neutral gray styling (no element colors)
+		&.neutral {
+			--toggle-active-bg: var(--button-bg);
+			--toggle-active-bg-hover: var(--button-bg-hover);
+			--toggle-active-icon: var(--text-primary);
+		}
+	}
+
+	.toggle-btn {
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		padding: $unit-half;
+		border: none;
+		background: transparent;
+		border-radius: $item-corner-small;
+		cursor: pointer;
+		color: var(--text-secondary);
+		@include smooth-transition($duration-instant, all);
+
+		&:hover:not(.active) {
+			color: var(--text-tertiary);
+			background: var(--button-bg-hover);
+		}
+
+		&:focus-visible {
+			@include focus-ring;
+		}
+
+		&.active {
+			background: var(--toggle-active-bg);
+			color: var(--toggle-active-icon);
+
+			&:hover {
+				background: var(--toggle-active-bg-hover);
+			}
+		}
+	}
+</style>