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.

app/api/listings/[id]/route.ts

@@ -6,6 +6,7 @@ import {
   updateListing,
   deleteListing,
 } from "@/lib/prisma/queries/listings";
+import { hasPendingIntention } from "@/lib/prisma/queries/purchase-intentions";
 import { updateListingSchema } from "@/lib/validation-schemas";
 
 /**
@@ -17,6 +18,7 @@ export async function GET(
   { params }: { params: Promise<{ id: string }> }
 ) {
   try {
+    const auth = await optionalAuth(request);
     const { id } = await params;
     const listingId = parseInt(id, 10);
 
@@ -42,10 +44,18 @@ export async function GET(
       );
     }
 
+    const hasPendingForUser =
+      auth && auth.userId
+        ? await hasPendingIntention(listingId, auth.userId)
+        : false;
+
     return NextResponse.json(
       {
         success: true,
-        listing,
+        listing: {
+          ...listing,
+          has_pending_intention_for_current_user: hasPendingForUser,
+        },
       },
       { status: 200 }
     );