Fix PR 3 review findings [skip ci]

crates/shared/src/lib.rs

@@ -690,6 +690,8 @@ pub struct UserPost {
     pub content: String,
     pub image_url: Option<String>,
     pub likes_count: i64,
+    #[serde(default)]
+    pub liked_by_me: bool,
     pub created_at: String,
 }