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/chat/MessageBubble.tsx

@@ -0,0 +1,63 @@
+"use client";
+
+import { cn } from "@/lib/utils";
+import type { ChatMessage } from "@/lib/hooks/use-chat";
+
+interface MessageBubbleProps {
+  message: ChatMessage;
+  isOwn: boolean;
+}
+
+function formatTime(date: string): string {
+  const d = new Date(date);
+  return d.toLocaleTimeString("pt-BR", {
+    hour: "2-digit",
+    minute: "2-digit",
+  });
+}
+
+export function MessageBubble({ message, isOwn }: MessageBubbleProps) {
+  if (message.message_type === "system") {
+    return (
+      <div className="flex justify-center my-2">
+        <span className="text-xs text-muted-foreground bg-muted px-3 py-1 rounded-full">
+          {message.content}
+        </span>
+      </div>
+    );
+  }
+
+  return (
+    <div
+      className={cn(
+        "flex w-full mb-2",
+        isOwn ? "justify-end" : "justify-start"
+      )}
+    >
+      <div
+        className={cn(
+          "max-w-[70%] rounded-lg px-4 py-2",
+          isOwn
+            ? "bg-primary text-primary-foreground"
+            : "bg-muted text-foreground"
+        )}
+      >
+        <p className="text-sm whitespace-pre-wrap break-words">
+          {message.content}
+        </p>
+        <div
+          className={cn(
+            "flex items-center gap-1 mt-1 text-xs",
+            isOwn ? "text-primary-foreground/70" : "text-muted-foreground"
+          )}
+        >
+          <span>{formatTime(message.created_at)}</span>
+          {isOwn && message.read_at && (
+            <span className="opacity-70">✓✓</span>
+          )}
+        </div>
+      </div>
+    </div>
+  );
+}
+