feat(market): add Minha Intenções tab with panel, hook, and badge

- Introduced "Minhas Intenções" tab visible only to logged-in users.
- Integrated MyPurchaseIntentionsPanel and useMyPurchaseIntentions hook.
- Added tab badge showing count of pending intentions.
- Extended session API to include user’s main character for downstream features.

components/messages/ChatListItem.tsx

@@ -0,0 +1,101 @@
+"use client";
+
+import { Card } from "@/components/ui/card";
+import { Badge } from "@/components/ui/badge";
+import { Avatar, AvatarFallback } from "@/components/ui/avatar";
+import { Package, Clock } from "lucide-react";
+import Image from "next/image";
+import type { Chat } from "@/lib/hooks/use-chat";
+import { formatTimeAgo } from "@/lib/utils";
+
+interface ChatListItemProps {
+  chat: Chat;
+  currentUserId: number;
+  onChatClick: () => void;
+}
+
+export function ChatListItem({
+  chat,
+  currentUserId,
+  onChatClick,
+}: ChatListItemProps) {
+  const otherUser =
+    chat.buyer_id === currentUserId
+      ? chat.seller_cache
+      : chat.buyer_cache;
+
+  const unreadCount =
+    chat.buyer_id === currentUserId
+      ? chat.buyer_unread_count
+      : chat.seller_unread_count;
+
+  const listing = chat.listing_cache;
+
+  return (
+    <Card
+      className="p-4 cursor-pointer hover:bg-accent transition-colors"
+      onClick={onChatClick}
+    >
+      <div className="flex items-start gap-3">
+        {/* Avatar do outro usuário */}
+        <Avatar className="h-12 w-12 flex-shrink-0">
+          <AvatarFallback>
+            {(otherUser.character_name || otherUser.username)
+              .charAt(0)
+              .toUpperCase()}
+          </AvatarFallback>
+        </Avatar>
+
+        {/* Conteúdo */}
+        <div className="flex-1 min-w-0">
+          <div className="flex items-center justify-between mb-1">
+            <h4 className="font-semibold text-sm truncate">
+              {otherUser.character_name || otherUser.username}
+            </h4>
+            {unreadCount > 0 && (
+              <Badge variant="destructive" className="h-5 min-w-5 px-1.5 text-xs">
+                {unreadCount}
+              </Badge>
+            )}
+          </div>
+
+          {/* Preview do item */}
+          <div className="flex items-center gap-2 text-xs text-muted-foreground mb-1">
+            <Package className="h-3 w-3 flex-shrink-0" />
+            <span className="truncate">{listing.item_name}</span>
+          </div>
+
+          {/* Preview da última mensagem */}
+          {chat.last_message_preview && (
+            <p className="text-xs text-muted-foreground truncate mb-1">
+              {chat.last_message_preview}
+            </p>
+          )}
+
+          {/* Timestamp */}
+          {chat.last_message_at && (
+            <div className="flex items-center gap-1 text-xs text-muted-foreground">
+              <Clock className="h-3 w-3" />
+              <span>{formatTimeAgo(new Date(chat.last_message_at))}</span>
+            </div>
+          )}
+        </div>
+
+        {/* Imagem do item (opcional) */}
+        {listing.item_image_url && (
+          <div className="relative w-12 h-12 rounded-lg bg-muted flex-shrink-0 overflow-hidden">
+            <Image
+              src={listing.item_image_url}
+              alt={listing.item_name}
+              fill
+              className="object-cover"
+              onError={(e) => {
+                e.currentTarget.style.display = "none";
+              }}
+            />
+          </div>
+        )}
+      </div>
+    </Card>
+  );
+}