refactor(calendar): simplify swipe to instant navigation

Remove all animation complexity - just instant page switches:
- Swipe/scroll threshold triggers immediate navigation
- No animation, no bounce, no transitions
- Accumulated delta for trackpad scrolling
- ~100 lines instead of ~300

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/calendar/apps/web/src/lib/components/calendar/ViewCarousel.svelte

@@ -1,7 +1,6 @@
 <script lang="ts">
 	import { browser } from '$app/environment';
 	import { viewStore } from '$lib/stores/view.svelte';
-	import { getOffsetDate } from '$lib/utils/dateNavigation';
 	import WeekView from './WeekView.svelte';
 	import DayView from './DayView.svelte';
 	import MonthView from './MonthView.svelte';
@@ -18,39 +17,16 @@
 
 	let { onQuickCreate, onEventClick, disableSwipe = false }: Props = $props();
 
-	// Swipe tracking state
-	let offsetX = $state(0);
-	let startX = $state(0);
-	let isSwiping = $state(false);
-	let isAnimating = $state(false);
-	let animatingDirection: 'prev' | 'next' | null = null;
+	// Swipe tracking
+	let startX = 0;
+	let isSwiping = false;
 
-	// Velocity tracking for momentum
-	let lastX = 0;
-	let lastTime = 0;
-	let velocity = 0;
-
-	// Animation frame tracking
-	let animationFrameId: number | null = null;
-	let pendingCallback: (() => void) | null = null;
-
-	// Container refs
+	// Container ref
 	let viewportEl: HTMLDivElement;
 	let viewportWidth = $state(0);
 
-	// Threshold: 15% of viewport width or high velocity triggers navigation
+	// Threshold: 15% of viewport width triggers navigation
 	const SNAP_THRESHOLD = 0.15;
-	const VELOCITY_THRESHOLD = 0.5; // px/ms - increased for faster swipes
-	// Animation speed (px/ms) - constant speed for linear feel
-	const ANIMATION_SPEED = 3.0; // increased for snappier feel
-	// Debounce for wheel events
-	const WHEEL_DEBOUNCE_MS = 50; // reduced for faster response
-	let wheelDebounceTimer: ReturnType<typeof setTimeout> | null = null;
-
-	// Calculate dates for previous/current/next views
-	let prevDate = $derived(getOffsetDate(viewStore.currentDate, viewStore.viewType, -1));
-	let currentDate = $derived(viewStore.currentDate);
-	let nextDate = $derived(getOffsetDate(viewStore.currentDate, viewStore.viewType, 1));
 
 	// Update viewport width on mount and resize
 	$effect(() => {
@@ -69,10 +45,12 @@
 	});
 
 	// Wheel handler (trackpad horizontal scroll)
+	let accumulatedDelta = 0;
+
 	function handleWheel(e: WheelEvent) {
 		if (disableSwipe) return;
 
-		// Only handle horizontal scrolling (deltaX dominant)
+		// Only handle horizontal scrolling
 		if (Math.abs(e.deltaX) <= Math.abs(e.deltaY)) return;
 
 		// Don't interfere with event dragging
@@ -81,208 +59,48 @@
 
 		e.preventDefault();
 
-		// If animating, check if we should chain navigation
-		if (isAnimating) {
-			const scrollDirection = e.deltaX < 0 ? 'next' : 'prev';
-			if (scrollDirection === animatingDirection && Math.abs(e.deltaX) > 10) {
-				// Chain navigation - immediately go to next page in same direction
-				chainNavigation(scrollDirection);
-			}
-			return;
+		accumulatedDelta += e.deltaX;
+
+		const threshold = viewportWidth * SNAP_THRESHOLD;
+
+		if (accumulatedDelta > threshold) {
+			viewStore.goToNext();
+			accumulatedDelta = 0;
+		} else if (accumulatedDelta < -threshold) {
+			viewStore.goToPrevious();
+			accumulatedDelta = 0;
 		}
-
-		// Simple direct offset update
-		offsetX += e.deltaX * -1;
-		offsetX = Math.max(-viewportWidth, Math.min(viewportWidth, offsetX));
-
-		// Debounced snap
-		if (wheelDebounceTimer) clearTimeout(wheelDebounceTimer);
-		wheelDebounceTimer = setTimeout(snapToPage, WHEEL_DEBOUNCE_MS);
 	}
 
 	// Touch handlers
 	function handleTouchStart(e: TouchEvent) {
-		if (disableSwipe || isAnimating) return;
+		if (disableSwipe) return;
 
-		// Don't interfere with event dragging
 		const target = e.target as HTMLElement;
 		if (target.closest('[data-event-id]') || target.closest('[data-dragging]')) return;
 
 		startX = e.touches[0].clientX;
-		lastX = startX;
-		lastTime = performance.now();
-		velocity = 0;
 		isSwiping = true;
-
-		if (wheelDebounceTimer) {
-			clearTimeout(wheelDebounceTimer);
-			wheelDebounceTimer = null;
-		}
 	}
 
-	function handleTouchMove(e: TouchEvent) {
-		if (!isSwiping || disableSwipe) return;
-
-		const currentX = e.touches[0].clientX;
-		const currentTime = performance.now();
-
-		// Calculate velocity (px/ms)
-		const dt = currentTime - lastTime;
-		if (dt > 0) {
-			velocity = (currentX - lastX) / dt;
-		}
-
-		lastX = currentX;
-		lastTime = currentTime;
-
-		offsetX = currentX - startX;
-		offsetX = Math.max(-viewportWidth, Math.min(viewportWidth, offsetX));
-	}
-
-	function handleTouchEnd() {
+	function handleTouchEnd(e: TouchEvent) {
 		if (!isSwiping) return;
 		isSwiping = false;
-		snapToPage();
+
+		const endX = e.changedTouches[0].clientX;
+		const deltaX = endX - startX;
+		const threshold = viewportWidth * SNAP_THRESHOLD;
+
+		if (deltaX > threshold) {
+			viewStore.goToPrevious();
+		} else if (deltaX < -threshold) {
+			viewStore.goToNext();
+		}
 	}
 
 	function handleTouchCancel() {
-		if (!isSwiping) return;
 		isSwiping = false;
-		isAnimating = true;
-		animateToOffset(0, () => {
-			isAnimating = false;
-		});
 	}
-
-	// Chain navigation - immediately complete current and start next
-	function chainNavigation(direction: 'prev' | 'next') {
-		// Cancel current animation
-		if (animationFrameId !== null) {
-			cancelAnimationFrame(animationFrameId);
-			animationFrameId = null;
-		}
-
-		// Complete current navigation immediately (without resetting state flags)
-		if (animatingDirection === 'prev') {
-			viewStore.goToPrevious();
-		} else if (animatingDirection === 'next') {
-			viewStore.goToNext();
-		}
-
-		// Reset and start new animation for another page in same direction
-		offsetX = direction === 'prev' ? viewportWidth * 0.4 : -viewportWidth * 0.4;
-		animatingDirection = direction;
-
-		const targetOffset = direction === 'prev' ? viewportWidth : -viewportWidth;
-		pendingCallback = () => {
-			if (direction === 'prev') {
-				viewStore.goToPrevious();
-			} else {
-				viewStore.goToNext();
-			}
-			offsetX = 0;
-			isAnimating = false;
-			animatingDirection = null;
-			pendingCallback = null;
-		};
-
-		animateToOffset(targetOffset, pendingCallback);
-	}
-
-	// Snap to page based on current offset and velocity
-	function snapToPage() {
-		if (isAnimating || viewportWidth === 0) return;
-
-		const threshold = viewportWidth * SNAP_THRESHOLD;
-		const hasHighVelocity = Math.abs(velocity) > VELOCITY_THRESHOLD;
-
-		// Determine direction based on position and velocity
-		let targetPage: 'prev' | 'next' | 'current' = 'current';
-
-		if (offsetX > threshold || (hasHighVelocity && velocity > 0 && offsetX > 0)) {
-			targetPage = 'prev';
-		} else if (offsetX < -threshold || (hasHighVelocity && velocity < 0 && offsetX < 0)) {
-			targetPage = 'next';
-		}
-
-		isAnimating = true;
-		animatingDirection = targetPage === 'current' ? null : targetPage;
-
-		if (targetPage === 'prev') {
-			pendingCallback = () => {
-				viewStore.goToPrevious();
-				offsetX = 0;
-				isAnimating = false;
-				animatingDirection = null;
-				pendingCallback = null;
-			};
-			animateToOffset(viewportWidth, pendingCallback);
-		} else if (targetPage === 'next') {
-			pendingCallback = () => {
-				viewStore.goToNext();
-				offsetX = 0;
-				isAnimating = false;
-				animatingDirection = null;
-				pendingCallback = null;
-			};
-			animateToOffset(-viewportWidth, pendingCallback);
-		} else {
-			pendingCallback = () => {
-				isAnimating = false;
-				animatingDirection = null;
-				pendingCallback = null;
-			};
-			animateToOffset(0, pendingCallback);
-		}
-	}
-
-	function animateToOffset(targetX: number, onComplete: () => void) {
-		// Cancel any existing animation
-		if (animationFrameId !== null) {
-			cancelAnimationFrame(animationFrameId);
-		}
-
-		const startX = offsetX;
-		const distance = targetX - startX;
-		const direction = Math.sign(distance);
-		const absDistance = Math.abs(distance);
-
-		// If already at target, complete immediately
-		if (absDistance < 1) {
-			offsetX = targetX;
-			onComplete();
-			return;
-		}
-
-		let lastFrameTime = performance.now();
-
-		function tick() {
-			const now = performance.now();
-			const dt = now - lastFrameTime;
-			lastFrameTime = now;
-
-			// Move at constant speed
-			const step = ANIMATION_SPEED * dt * direction;
-			offsetX += step;
-
-			// Check if we've reached or passed the target
-			const reachedTarget =
-				(direction > 0 && offsetX >= targetX) || (direction < 0 && offsetX <= targetX);
-
-			if (reachedTarget) {
-				offsetX = targetX;
-				animationFrameId = null;
-				onComplete();
-			} else {
-				animationFrameId = requestAnimationFrame(tick);
-			}
-		}
-
-		animationFrameId = requestAnimationFrame(tick);
-	}
-
-	// Computed styles
-	let trackStyle = $derived(`transform: translateX(calc(-33.333% + ${offsetX}px))`);
 </script>
 
 <!-- svelte-ignore a11y_no_static_element_interactions -->
@@ -291,76 +109,28 @@
 	bind:this={viewportEl}
 	onwheel={handleWheel}
 	ontouchstart={handleTouchStart}
-	ontouchmove={handleTouchMove}
 	ontouchend={handleTouchEnd}
 	ontouchcancel={handleTouchCancel}
 >
-	<div class="carousel-track" style={trackStyle}>
-		<!-- Previous View -->
-		<div class="carousel-page" class:inactive={!isSwiping && offsetX <= 0}>
-			{#if viewStore.viewType === 'day'}
-				<DayView date={prevDate} />
-			{:else if viewStore.viewType === '5day'}
-				<MultiDayView dayCount={5} date={prevDate} />
-			{:else if viewStore.viewType === 'week'}
-				<WeekView date={prevDate} />
-			{:else if viewStore.viewType === '10day'}
-				<MultiDayView dayCount={10} date={prevDate} />
-			{:else if viewStore.viewType === '14day'}
-				<MultiDayView dayCount={14} date={prevDate} />
-			{:else if viewStore.viewType === 'month'}
-				<MonthView date={prevDate} />
-			{:else if viewStore.viewType === 'year'}
-				<YearView date={prevDate} />
-			{:else if viewStore.viewType === 'agenda'}
-				<AgendaView date={prevDate} />
-			{/if}
-		</div>
-
-		<!-- Current View (main interactive view) -->
-		<div class="carousel-page current">
-			{#if viewStore.viewType === 'day'}
-				<DayView {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === '5day'}
-				<MultiDayView dayCount={5} {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === 'week'}
-				<WeekView {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === '10day'}
-				<MultiDayView dayCount={10} {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === '14day'}
-				<MultiDayView dayCount={14} {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === 'month'}
-				<MonthView {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === 'year'}
-				<YearView {onQuickCreate} {onEventClick} />
-			{:else if viewStore.viewType === 'agenda'}
-				<AgendaView {onEventClick} />
-			{:else}
-				<WeekView {onQuickCreate} {onEventClick} />
-			{/if}
-		</div>
-
-		<!-- Next View -->
-		<div class="carousel-page" class:inactive={!isSwiping && offsetX >= 0}>
-			{#if viewStore.viewType === 'day'}
-				<DayView date={nextDate} />
-			{:else if viewStore.viewType === '5day'}
-				<MultiDayView dayCount={5} date={nextDate} />
-			{:else if viewStore.viewType === 'week'}
-				<WeekView date={nextDate} />
-			{:else if viewStore.viewType === '10day'}
-				<MultiDayView dayCount={10} date={nextDate} />
-			{:else if viewStore.viewType === '14day'}
-				<MultiDayView dayCount={14} date={nextDate} />
-			{:else if viewStore.viewType === 'month'}
-				<MonthView date={nextDate} />
-			{:else if viewStore.viewType === 'year'}
-				<YearView date={nextDate} />
-			{:else if viewStore.viewType === 'agenda'}
-				<AgendaView date={nextDate} />
-			{/if}
-		</div>
-	</div>
+	{#if viewStore.viewType === 'day'}
+		<DayView {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === '5day'}
+		<MultiDayView dayCount={5} {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === 'week'}
+		<WeekView {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === '10day'}
+		<MultiDayView dayCount={10} {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === '14day'}
+		<MultiDayView dayCount={14} {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === 'month'}
+		<MonthView {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === 'year'}
+		<YearView {onQuickCreate} {onEventClick} />
+	{:else if viewStore.viewType === 'agenda'}
+		<AgendaView {onEventClick} />
+	{:else}
+		<WeekView {onQuickCreate} {onEventClick} />
+	{/if}
 </div>
 
 <style>
@@ -371,28 +141,4 @@
 		position: relative;
 		touch-action: pan-y;
 	}
-
-	.carousel-track {
-		display: flex;
-		width: 300%;
-		height: 100%;
-		will-change: transform;
-	}
-
-	.carousel-page {
-		width: 33.333%;
-		height: 100%;
-		flex-shrink: 0;
-		overflow: hidden;
-	}
-
-	/* Inactive pages have reduced interactivity for performance */
-	.carousel-page.inactive {
-		pointer-events: none;
-	}
-
-	.carousel-page.current {
-		/* Always interactive */
-		pointer-events: auto;
-	}
 </style>