feat(calendar): add birthday calendar and collapsible date strip

- Add virtual birthday calendar to calendars store
- Create DateStripFab component for collapsed date strip mode
- Add dateStripCollapsed setting support in layout
- Adjust InputBar positioning for FAB visibility

🤖 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/DateStripFab.svelte

@@ -0,0 +1,113 @@
+<script lang="ts">
+	import { settingsStore } from '$lib/stores/settings.svelte';
+	import { format } from 'date-fns';
+	import { de } from 'date-fns/locale';
+	import DateStripContextMenu from './DateStripContextMenu.svelte';
+
+	interface Props {
+		isSidebarMode?: boolean;
+		isToolbarExpanded?: boolean;
+	}
+
+	let { isSidebarMode = false, isToolbarExpanded = false }: Props = $props();
+
+	let contextMenu: DateStripContextMenu;
+
+	function handleClick() {
+		settingsStore.set('dateStripCollapsed', false);
+	}
+
+	function handleContextMenu(e: MouseEvent) {
+		e.preventDefault();
+		contextMenu?.show(e.clientX, e.clientY);
+	}
+
+	// Format current date for FAB display: "Dez 14"
+	let fabLabel = $derived(format(new Date(), 'MMM d', { locale: de }));
+</script>
+
+<div
+	class="datestrip-fab-container"
+	class:sidebar-mode={isSidebarMode}
+	class:toolbar-expanded={isToolbarExpanded}
+>
+	<!-- svelte-ignore a11y_no_static_element_interactions -->
+	<button
+		onclick={handleClick}
+		oncontextmenu={handleContextMenu}
+		class="datestrip-fab"
+		title="Datumsleiste erweitern (Rechtsklick für Optionen)"
+	>
+		<span class="fab-label">{fabLabel}</span>
+	</button>
+</div>
+
+<DateStripContextMenu bind:this={contextMenu} />
+
+<style>
+	.datestrip-fab-container {
+		position: fixed;
+		bottom: calc(70px + 9px + env(safe-area-inset-bottom, 0px));
+		/* Position left of InputBar: center (50%) minus half of InputBar (225px) minus gap (8px) minus fab width (54px) */
+		left: calc(50% - 225px - 8px - 54px);
+		z-index: 49;
+		pointer-events: none;
+		transition:
+			bottom 0.2s ease,
+			left 0.2s ease;
+	}
+
+	.datestrip-fab-container.sidebar-mode {
+		bottom: calc(9px + env(safe-area-inset-bottom, 0px));
+		/* In sidebar mode, InputBar is 700px wide, so position accordingly */
+		left: calc(50% - 350px - 8px - 54px);
+	}
+
+	.datestrip-fab-container.toolbar-expanded {
+		bottom: calc(140px + 9px + env(safe-area-inset-bottom, 0px));
+	}
+
+	.datestrip-fab-container.sidebar-mode.toolbar-expanded {
+		bottom: calc(70px + 9px + env(safe-area-inset-bottom, 0px));
+		/* In sidebar mode, InputBar is 700px wide */
+		left: calc(50% - 350px - 8px - 54px);
+	}
+
+	@media (max-width: 900px) {
+		.datestrip-fab-container {
+			left: 1rem;
+		}
+	}
+
+	.datestrip-fab {
+		display: flex;
+		flex-direction: column;
+		align-items: center;
+		justify-content: center;
+		min-width: 54px;
+		height: 54px;
+		padding: 0 0.75rem;
+		cursor: pointer;
+		border: none;
+		transition: all 0.2s ease;
+		pointer-events: auto;
+		background: hsl(var(--color-surface) / 0.85);
+		backdrop-filter: blur(12px);
+		-webkit-backdrop-filter: blur(12px);
+		border: 1px solid hsl(var(--color-border));
+		box-shadow: 0 2px 8px hsl(var(--color-foreground) / 0.08);
+		border-radius: 9999px;
+	}
+
+	.datestrip-fab:hover {
+		transform: scale(1.05);
+		box-shadow: 0 4px 12px hsl(var(--color-foreground) / 0.15);
+	}
+
+	.fab-label {
+		font-size: 0.875rem;
+		font-weight: 600;
+		color: hsl(var(--color-foreground));
+		white-space: nowrap;
+	}
+</style>

apps/calendar/apps/web/src/lib/stores/calendars.svelte.ts

@@ -4,18 +4,42 @@
 
 import type { Calendar, CreateCalendarInput, UpdateCalendarInput } from '@calendar/shared';
 import * as api from '$lib/api/calendars';
+import { BIRTHDAY_CALENDAR } from '$lib/api/birthdays';
+import { settingsStore } from './settings.svelte';
 
 // State
 let calendars = $state<Calendar[]>([]);
 let loading = $state(false);
 let error = $state<string | null>(null);
 
+// Virtual birthday calendar (created dynamically based on settings)
+const birthdayCalendar: Calendar = {
+	id: BIRTHDAY_CALENDAR.id,
+	userId: '',
+	name: BIRTHDAY_CALENDAR.name,
+	color: BIRTHDAY_CALENDAR.color,
+	isDefault: false,
+	isVisible: true, // Visibility controlled by settingsStore.showBirthdays
+	createdAt: new Date().toISOString(),
+	updatedAt: new Date().toISOString(),
+};
+
 // Helper to safely get calendars array (Svelte 5 runes safety)
 function getCalendarsArray(): Calendar[] {
 	const arr = calendars ?? [];
 	return Array.isArray(arr) ? arr : [];
 }
 
+// Derived: all calendars including virtual birthday calendar
+const allCalendars = $derived.by(() => {
+	const userCalendars = getCalendarsArray();
+	// Add virtual birthday calendar if birthdays are enabled in settings
+	if (settingsStore.showBirthdays) {
+		return [...userCalendars, { ...birthdayCalendar, isVisible: true }];
+	}
+	return userCalendars;
+});
+
 // Derived: visible calendars
 const visibleCalendars = $derived(getCalendarsArray().filter((c) => c.isVisible));
 
@@ -30,6 +54,9 @@ export const calendarsStore = {
 	get calendars() {
 		return calendars;
 	},
+	get allCalendars() {
+		return allCalendars;
+	},
 	get visibleCalendars() {
 		return visibleCalendars;
 	},
@@ -42,6 +69,9 @@ export const calendarsStore = {
 	get error() {
 		return error;
 	},
+	get birthdayCalendarId() {
+		return BIRTHDAY_CALENDAR.id;
+	},
 
 	/**
 	 * Fetch all calendars
@@ -143,7 +173,26 @@ export const calendarsStore = {
 	 * Get calendar color by ID (with fallback)
 	 */
 	getColor(id: string) {
+		// Handle virtual birthday calendar
+		if (id === BIRTHDAY_CALENDAR.id) {
+			return BIRTHDAY_CALENDAR.color;
+		}
 		const calendar = getCalendarsArray().find((c) => c.id === id);
 		return calendar?.color || '#3b82f6';
 	},
+
+	/**
+	 * Toggle birthday calendar visibility
+	 * (This updates the settings store, not the calendar itself)
+	 */
+	toggleBirthdaysVisibility() {
+		settingsStore.set('showBirthdays', !settingsStore.showBirthdays);
+	},
+
+	/**
+	 * Check if a calendar ID is the virtual birthday calendar
+	 */
+	isBirthdayCalendar(id: string) {
+		return id === BIRTHDAY_CALENDAR.id;
+	},
 };

apps/calendar/apps/web/src/routes/(app)/+layout.svelte

@@ -52,6 +52,7 @@
 	import CalendarToolbar from '$lib/components/calendar/CalendarToolbar.svelte';
 	import CalendarToolbarContent from '$lib/components/calendar/CalendarToolbarContent.svelte';
 	import DateStrip from '$lib/components/calendar/DateStrip.svelte';
+	import DateStripFab from '$lib/components/calendar/DateStripFab.svelte';
 	import EventContextMenu from '$lib/components/event/EventContextMenu.svelte';
 	import { eventContextMenuStore } from '$lib/stores/eventContextMenu.svelte';
 
@@ -387,8 +388,12 @@
 
 		<!-- Date strip (only on main calendar page) -->
 		{#if showCalendarToolbar}
+			{#if settingsStore.dateStripCollapsed}
+				<DateStripFab {isSidebarMode} isToolbarExpanded={!isToolbarCollapsed} />
+			{:else}
 				<DateStrip {isSidebarMode} isToolbarExpanded={!isToolbarCollapsed} />
 			{/if}
+		{/if}
 
 		<!-- Calendar toolbar (only on main calendar page, not in sidebar mode) -->
 		{#if showCalendarToolbar && !isSidebarMode}
@@ -433,6 +438,7 @@
 					? '140px'
 					: '70px'}
 			hasFabRight={showCalendarToolbar && !isSidebarMode}
+			hasFabLeft={showCalendarToolbar && !isSidebarMode && settingsStore.dateStripCollapsed}
 		/>
 	</div>
 </SplitPaneContainer>
@@ -517,4 +523,32 @@
 		flex: 1;
 		min-height: 0;
 	}
+
+	/* Adjust InputBar when FABs are visible (toolbar FAB on right, DateStripFab on left) */
+	/* For a centered InputBar with max-width 450px, left edge is at 50% - 225px */
+	/* DateStripFab is positioned at: 50% - 225px - 8px gap - 54px fab width */
+	/* Note: In sidebar mode, InputBar uses default 700px max-width */
+	:global(.quick-input-bar.has-fab-right .input-container),
+	:global(.quick-input-bar.has-fab-left .input-container) {
+		max-width: 450px;
+	}
+
+	/* On smaller screens (<900px), FABs move to fixed positions (left: 1rem, right: 1rem) */
+	@media (max-width: 900px) {
+		:global(.quick-input-bar.has-fab-right .input-container) {
+			max-width: calc(100% - 140px); /* 54px FAB + padding */
+			margin-left: auto;
+			margin-right: 0;
+		}
+		:global(.quick-input-bar.has-fab-left .input-container) {
+			max-width: calc(100% - 140px); /* 54px FAB + padding */
+			margin-left: 0;
+			margin-right: auto;
+		}
+		:global(.quick-input-bar.has-fab-right.has-fab-left .input-container) {
+			max-width: calc(100% - 200px); /* Both FABs */
+			margin-left: auto;
+			margin-right: auto;
+		}
+	}
 </style>