feat(frontend): polish allocation report filters

Improve filter bar layout and multi-select UX:
- Add MultiSelectDropdown component with tag-based selection
- Fix filter grid alignment for consistent spacing
- Update allocation report page with improved filter styling

Part of enhanced-allocation UI polish.

frontend/src/lib/components/common/MultiSelectDropdown.svelte

@@ -0,0 +1,107 @@
+<script lang="ts">
+	import { createEventDispatcher, onMount } from 'svelte';
+
+	interface Option {
+		id: string;
+		label: string;
+	}
+
+	const dispatch = createEventDispatcher<{ change: string[] }>();
+
+	export let label = '';
+	export let options: Option[] = [];
+	export let selected: string[] = [];
+	export let placeholder = 'Select options';
+	export let disabled = false;
+
+	let open = false;
+	let container: HTMLDivElement | null = null;
+
+	function updateSelection(values: string[]) {
+		selected = values;
+		dispatch('change', selected);
+	}
+
+	function toggleValue(id: string) {
+		const values = selected.includes(id)
+			? selected.filter((value) => value !== id)
+			: [...selected, id];
+		updateSelection(values);
+	}
+
+	function removeValue(id: string) {
+		const values = selected.filter((value) => value !== id);
+		updateSelection(values);
+	}
+
+	function handleOutsideClick(event: MouseEvent) {
+		if (container && !container.contains(event.target as Node)) {
+			open = false;
+		}
+	}
+
+	onMount(() => {
+		document.addEventListener('click', handleOutsideClick);
+		return () => document.removeEventListener('click', handleOutsideClick);
+	});
+</script>
+
+<div class="flex flex-col gap-1.5" bind:this={container}>
+	{#if label}
+		<label class="text-xs font-semibold text-gray-500 uppercase tracking-wide">{label}</label>
+	{/if}
+	<div class="relative">
+		<button
+			type="button"
+			class={`w-full rounded-md border bg-white px-3 py-[0.4375rem] text-sm flex items-center justify-between gap-2 transition focus:outline-none focus:ring-2 focus:ring-indigo-500/20 ${disabled ? 'border-gray-200 text-gray-400 cursor-not-allowed' : 'border-gray-300 text-gray-900 shadow-sm hover:border-indigo-400'}`}
+			aria-haspopup="listbox"
+			aria-expanded={open}
+			on:click|stopPropagation={() => {
+				if (disabled) return;
+				open = !open;
+			}}
+		>
+			<div class="flex-1 flex flex-wrap gap-1.5 items-center min-h-[1.375rem]">
+				{#if selected.length === 0}
+					<span class="text-sm text-gray-400">{placeholder}</span>
+				{:else}
+					{#each selected as id}
+						<span class="inline-flex items-center gap-1 rounded border border-indigo-200 bg-indigo-50 px-2 py-0.5 text-xs font-medium text-indigo-800 whitespace-nowrap">
+							{options.find((option) => option.id === id)?.label ?? id}
+							<button
+								type="button"
+								class="text-indigo-400 hover:text-indigo-700 focus:outline-none ml-0.5"
+								on:click|preventDefault|stopPropagation={() => removeValue(id)}
+							>
+								×
+							</button>
+						</span>
+					{/each}
+				{/if}
+			</div>
+			<span class="text-gray-400 shrink-0">▾</span>
+		</button>
+		{#if open}
+			<div
+				class="absolute z-10 mt-1 w-full max-h-60 overflow-auto rounded-md border border-gray-200 bg-white shadow-lg"
+				on:click|stopPropagation
+			>
+				{#if options.length === 0}
+					<p class="px-3 py-2 text-sm text-gray-500">No options available</p>
+				{:else}
+					{#each options as option}
+						<label class="flex items-center gap-3 px-3 py-2 text-sm text-gray-900 hover:bg-gray-50 cursor-pointer">
+							<input
+								type="checkbox"
+								checked={selected.includes(option.id)}
+								on:change={() => toggleValue(option.id)}
+								class="h-4 w-4 rounded border-gray-300 text-indigo-600 focus:ring-indigo-500"
+							/>
+							<span>{option.label}</span>
+						</label>
+					{/each}
+				{/if}
+			</div>
+		{/if}
+	</div>
+</div>

frontend/src/routes/reports/allocation/+page.svelte

@@ -1,7 +1,6 @@
 <script lang="ts">
 	import { onMount } from 'svelte';
 	import PageHeader from '$lib/components/layout/PageHeader.svelte';
-	import FilterBar from '$lib/components/common/FilterBar.svelte';
 	import LoadingState from '$lib/components/common/LoadingState.svelte';
 	import EmptyState from '$lib/components/common/EmptyState.svelte';
 	import { Calendar, FileText, AlertCircle, Users, FolderKanban } from 'lucide-svelte';
@@ -16,6 +15,8 @@
 	import { projectService, type Project } from '$lib/services/projectService';
 	import { teamMemberService, type TeamMember } from '$lib/services/teamMemberService';
 
+	import MultiSelectDropdown from '$lib/components/common/MultiSelectDropdown.svelte';
+
 	// State
 	let report = $state<ReportResponse | null>(null);
 	let projects = $state<Project[]>([]);
@@ -83,8 +84,29 @@
 		loadReport();
 	}
 
-	function formatHours(hours: number): string {
+	function parseDateString(value: string): Date {
-		return `${hours.toFixed(1)}h`;
+		const [year, month, day] = value.split('-').map(Number);
+		return new Date(year, month - 1, day);
+	}
+
+	function formatDisplayDate(value: string): string {
+		if (!value) return '';
+		const date = parseDateString(value);
+		return isNaN(date.getTime()) ? '' : date.toLocaleDateString();
+	}
+
+	function formatMonthLabel(value: string): string {
+		if (!value) return '';
+		const normalized = value.split('-').length === 3 ? value : `${value}-01`;
+		const date = parseDateString(normalized);
+		return isNaN(date.getTime())
+			? ''
+			: date.toLocaleDateString(undefined, { month: 'short', year: 'numeric' });
+	}
+
+	function formatHours(hours: number | null | undefined): string {
+		const value = typeof hours === 'number' && isFinite(hours) ? hours : 0;
+		return `${value.toFixed(1)}h`;
 	}
 
 	function getViewTypeBadgeClass(viewType: ViewType): string {
@@ -109,59 +131,67 @@
 />
 
 <!-- Filters -->
-<div class="bg-white rounded-lg shadow-sm border border-gray-200 p-4 mb-6">
+<div class="bg-white rounded-lg shadow-sm border border-gray-200 p-5 mb-6">
-	<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-5 gap-4 items-end">
+	<div class="grid grid-cols-[auto_auto_1fr_auto_auto] gap-x-4 gap-y-3 items-end max-lg:grid-cols-2 max-lg:gap-3 max-sm:grid-cols-1">
-		<div>
+		<!-- Start Date -->
-			<label class="block text-sm font-medium text-gray-700 mb-1">Start Date</label>
+		<div class="flex flex-col gap-1.5">
+			<label class="text-xs font-semibold text-gray-500 uppercase tracking-wide">Start Date</label>
 			<input
 				type="date"
 				bind:value={startDate}
-				class="w-full rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500"
+				class="w-full rounded-md border border-gray-300 bg-white px-3 py-[0.4375rem] text-sm text-gray-900 shadow-sm transition hover:border-indigo-400 focus:border-indigo-500 focus:ring-2 focus:ring-indigo-500/20 focus:outline-none"
 			/>
 		</div>
-		<div>
+
-			<label class="block text-sm font-medium text-gray-700 mb-1">End Date</label>
+		<!-- End Date -->
+		<div class="flex flex-col gap-1.5">
+			<label class="text-xs font-semibold text-gray-500 uppercase tracking-wide">End Date</label>
 			<input
 				type="date"
 				bind:value={endDate}
-				class="w-full rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500"
+				class="w-full rounded-md border border-gray-300 bg-white px-3 py-[0.4375rem] text-sm text-gray-900 shadow-sm transition hover:border-indigo-400 focus:border-indigo-500 focus:ring-2 focus:ring-indigo-500/20 focus:outline-none"
 			/>
 		</div>
-		<div>
+
-			<label class="block text-sm font-medium text-gray-700 mb-1">Projects</label>
+		<!-- Projects multi-select — fills remaining space -->
-			<select
+		<div class="min-w-0 max-lg:col-span-2 max-sm:col-span-1">
-				bind:value={selectedProjects}
+			<MultiSelectDropdown
-				multiple
+				label="Projects"
-				class="w-full rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500 h-10"
+				placeholder="All projects"
-			>
+				options={projects.map((project) => ({ id: project.id, label: `${project.code} - ${project.title}` }))}
-				{#each projects as project}
+				bind:selected={selectedProjects}
-					<option value={project.id}>{project.code} - {project.title}</option>
+			/>
-				{/each}
-			</select>
 		</div>
-		<div>
+
-			<label class="block text-sm font-medium text-gray-700 mb-1">View Mode</label>
+		<!-- View Mode -->
+		<div class="flex flex-col gap-1.5">
+			<label class="text-xs font-semibold text-gray-500 uppercase tracking-wide">View Mode</label>
 			<select
 				bind:value={viewMode}
-				class="w-full rounded-md border-gray-300 shadow-sm focus:border-indigo-500 focus:ring-indigo-500"
+				class="w-full rounded-md border border-gray-300 bg-white px-3 py-[0.4375rem] text-sm text-gray-900 shadow-sm transition hover:border-indigo-400 focus:border-indigo-500 focus:ring-2 focus:ring-indigo-500/20 focus:outline-none"
 			>
-				<option value="aggregate">📊 Aggregate</option>
+				<option value="aggregate">Aggregate</option>
-				<option value="detailed">📋 Detailed</option>
+				<option value="detailed">Detailed</option>
 			</select>
 		</div>
+
+		<!-- Apply -->
+		<div class="flex items-end">
 			<button
-			onclick={handleApplyFilters}
+				type="button"
+				on:click={handleApplyFilters}
 				disabled={loading || !startDate || !endDate}
-			class="inline-flex justify-center items-center px-4 py-2 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-indigo-600 hover:bg-indigo-700 disabled:bg-gray-300"
+				class="inline-flex items-center justify-center px-5 py-[0.4375rem] rounded-md text-sm font-medium text-white bg-indigo-600 shadow-sm transition hover:bg-indigo-700 active:bg-indigo-800 disabled:bg-gray-300 disabled:cursor-not-allowed focus:outline-none focus:ring-2 focus:ring-indigo-500/20 whitespace-nowrap"
 			>
 				{#if loading}
-				<span class="animate-spin mr-2">⟳</span> Loading...
+					<span class="animate-spin mr-2">⟳</span> Loading…
 				{:else}
 					Apply Filters
 				{/if}
 			</button>
 		</div>
 	</div>
+</div>
 
 <!-- Error State -->
 {#if error}
@@ -187,7 +217,7 @@
 			{formatViewType(report.view_type)}
 		</span>
 		<span class="text-sm text-gray-500">
-			Period: {new Date(report.period.start).toLocaleDateString()} - {new Date(report.period.end).toLocaleDateString()}
+			Period: {formatDisplayDate(report.period.start)} - {formatDisplayDate(report.period.end)}
 		</span>
 	</div>
 
@@ -319,7 +349,7 @@
 					<tbody class="divide-y divide-gray-200">
 						{#each project.months as month}
 							<tr class="hover:bg-gray-50">
-								<td class="px-4 py-2 text-sm text-gray-900">{new Date(month.month + '-01').toLocaleDateString(undefined, { month: 'short', year: 'numeric' })}</td>
+								<td class="px-4 py-2 text-sm text-gray-900">{formatMonthLabel(month.month)}</td>
 								<td class="px-4 py-2 text-right text-sm">
 									{#if month.is_blank}
 										<span class="text-gray-400 italic">blank</span>