fix: profile date, avatar system, UserRead schema

backend/schemas.py

@@ -18,6 +18,9 @@ class UserRead(SQLModel):
     profile_public: bool = True
     show_attendance_public: bool = True
     appear_in_leaderboards: bool = True
+    bio: Optional[str] = None
+    username: Optional[str] = None
+    joined_at: Optional[datetime] = None
 
 class Token(SQLModel):
     access_token: str

frontend/app/profile/[slug]/page.tsx

@@ -19,7 +19,7 @@ interface UserProfile {
     email: string
     username: string | null
     bio: string | null
-    created_at: string
+    joined_at: string | null
 }
 
 interface UserBadge {
@@ -97,16 +97,18 @@ export default function PublicProfilePage({ params }: { params: Promise<{ slug:
 
             <Card className="border-0 shadow-none bg-transparent">
                 <div className="flex flex-col md:flex-row gap-8 items-start">
-                    <Avatar className="h-32 w-32 border-4 border-background shadow-lg">
-                        <AvatarImage src={`https://api.dicebear.com/7.x/notionists/svg?seed=${user.id}`} />
-                        <AvatarFallback><User className="h-12 w-12" /></AvatarFallback>
-                    </Avatar>
+                    <div
+                        className="h-32 w-32 rounded-full border-4 border-background shadow-lg flex items-center justify-center text-white text-4xl font-bold"
+                        style={{ backgroundColor: (user as any).avatar_bg_color || '#3B82F6' }}
+                    >
+                        {(user as any).avatar_text || displayName.substring(0, 2).toUpperCase()}
+                    </div>
                     <div className="space-y-4 flex-1">
                         <div>
                             <h1 className="text-4xl font-bold tracking-tight">{displayName}</h1>
                             <p className="text-muted-foreground flex items-center gap-2 mt-2">
                                 <Calendar className="h-4 w-4" />
-                                Member since {new Date(user.created_at).toLocaleDateString()}
+                                Member since {user.joined_at ? new Date(user.joined_at).toLocaleDateString() : 'Unknown'}
                             </p>
                         </div>
                         {user.bio && (