fix(collections): tighten itinerary chat panel access and state scoping

frontend/src/lib/components/AITravelChat.svelte

@@ -88,7 +88,10 @@
 	}>();
 
 	const MODEL_PREFS_STORAGE_KEY = 'voyage_chat_model_prefs';
-	const ACTIVE_CONV_KEY = 'voyage_active_conversation';
+	const ACTIVE_CONV_FALLBACK_KEY = 'voyage_active_conversation';
+	$: activeConvKey = collectionId
+		? `voyage_active_conversation_${collectionId}`
+		: ACTIVE_CONV_FALLBACK_KEY;
 	$: promptTripContext = collectionName || destination || '';
 
 	onMount(() => {
@@ -138,9 +141,9 @@
 
 		try {
 			if (convId) {
-				window.localStorage.setItem(ACTIVE_CONV_KEY, convId);
+				window.localStorage.setItem(activeConvKey, convId);
 			} else {
-				window.localStorage.removeItem(ACTIVE_CONV_KEY);
+				window.localStorage.removeItem(activeConvKey);
 			}
 		} catch {
 			// ignore localStorage persistence failures
@@ -152,7 +155,7 @@
 			return;
 		}
 
-		const savedId = window.localStorage.getItem(ACTIVE_CONV_KEY);
+		const savedId = window.localStorage.getItem(activeConvKey);
 		if (!savedId) {
 			return;
 		}

frontend/src/routes/collections/[id]/+page.svelte

@@ -209,7 +209,7 @@
 	type ViewType = 'all' | 'itinerary' | 'map' | 'calendar' | 'recommendations' | 'stats';
 	let currentView: ViewType = 'itinerary';
 	let chatPanelOpen = false;
-	let innerWidth = 0;
+	let innerWidth = 1024;
 
 	// Determine if this is a folder view (no dates) or itinerary view (has dates)
 	$: isFolderView = !collection?.start_date && !collection?.end_date;
@@ -293,6 +293,10 @@
 	// Enforce recommendations visibility only for owner/shared users
 	$: availableViews.recommendations = !!canModifyCollection;
 
+	$: if (!canModifyCollection && chatPanelOpen) {
+		chatPanelOpen = false;
+	}
+
 	function deriveCollectionDestination(current: Collection | null): string | undefined {
 		if (!current?.locations?.length) {
 			return undefined;
@@ -766,6 +770,12 @@
 		isImageModalOpen = true;
 	}
 
+	function handleImageKeydown(event: KeyboardEvent, imageIndex: number) {
+		if (event.key === 'Enter') {
+			openImageModal(imageIndex);
+		}
+	}
+
 	function formatDate(dateString: string | null) {
 		if (!dateString) return '';
 		return DateTime.fromISO(dateString).toLocaleString(DateTime.DATE_MED, { locale: 'en-GB' });
@@ -1236,6 +1246,7 @@
 						</button>
 					{/if}
 				</div>
+				{#if canModifyCollection}
 					<button
 						class="btn btn-primary btn-sm gap-2 ml-4"
 						class:btn-outline={!chatPanelOpen}
@@ -1245,10 +1256,14 @@
 						<MessageCircle class="w-4 h-4" />
 						<span class="hidden sm:inline">{$t('chat.travel_assistant')}</span>
 					</button>
+				{/if}
 			</div>
 		</div>
 
-		<div class="drawer drawer-end" class:drawer-open={chatPanelOpen && innerWidth >= 1024}>
+		<div
+			class="drawer drawer-end"
+			class:drawer-open={canModifyCollection && chatPanelOpen && innerWidth >= 1024}
+		>
 			<input
 				id="collection-chat-drawer"
 				type="checkbox"
@@ -1259,7 +1274,7 @@
 			<div class="drawer-content">
 				<div class="grid grid-cols-1 lg:grid-cols-4 gap-6 sm:gap-10">
 					<!-- Left Column - Main Content -->
-					<div class="lg:col-span-3 space-y-8 sm:space-y-10">
+					<div class="{chatPanelOpen ? 'lg:col-span-4' : 'lg:col-span-3'} space-y-8 sm:space-y-10">
 						<!-- Description Card (always visible) -->
 						{#if collection.description}
 							<div class="card bg-base-200 shadow-xl">
@@ -1366,15 +1381,6 @@
 						<!-- Recommendations View -->
 						{#if currentView === 'recommendations'}
 							<div class="space-y-8">
-								<AITravelChat
-									embedded={true}
-									collectionId={collection.id}
-									collectionName={collection.name}
-									startDate={collection.start_date || undefined}
-									endDate={collection.end_date || undefined}
-									destination={collectionDestination}
-									on:itemAdded={handleAssistantItemAdded}
-								/>
 								<CollectionRecommendationView bind:collection user={data.user} />
 							</div>
 						{/if}
@@ -1632,7 +1638,7 @@
 														class="aspect-square bg-cover bg-center rounded-lg cursor-pointer transition-transform duration-200 group-hover:scale-105"
 														style="background-image: url({image.image})"
 														on:click={() => openImageModal(index)}
-														on:keydown={(e) => e.key === 'Enter' && openImageModal(index)}
+														on:keydown={(event) => handleImageKeydown(event, index)}
 														role="button"
 														tabindex="0"
 													></div>
@@ -1661,6 +1667,7 @@
 				</div>
 			</div>
 
+			{#if canModifyCollection}
 				<div class="drawer-side z-40">
 					<label for="collection-chat-drawer" class="drawer-overlay"></label>
 					<div class="bg-base-100 h-full w-full sm:w-96 border-l border-base-300 flex flex-col">
@@ -1687,13 +1694,14 @@
 						</div>
 					</div>
 				</div>
+			{/if}
 		</div>
 	</div>
 {/if}
 
 <!-- Floating Action Button (FAB) - Only shown if user can modify collection -->
 {#if collection && canModifyCollection && !collection.is_archived}
-	<div class="fixed bottom-6 right-6 z-[999]">
+	<div class="fixed bottom-6 right-6 {chatPanelOpen ? 'z-30' : 'z-[999]'}">
 		<div class="dropdown dropdown-top dropdown-end">
 			<div
 				tabindex="0"