add comments to note on unlisted notes

src/blog.rs

@@ -84,6 +84,8 @@ impl Post {
     // post is not found in PostsList, it must not be found
     // here either; if a post is found in PostsList, then
     // this method should not return any error.
+    // (except for hidden posts, in which case they won't be
+    //  present in PostsList)
     pub async fn find_by_uuid(uuid: &str) -> MyResult<Post> {
         store::get_obj(&Self::uuid_to_post_key(uuid)).await
     }

src/sn.rs

@@ -34,6 +34,7 @@ async fn get_actions(_req: Request, url: Url) -> MyResult<Response> {
     // Show different options depending on whether the post already exists
     // Use Post here because PostsList is larger to read into memory
     // also slower to check one-by-one
+    // (also, because it may be a hidden post that does not live in PostsList)
     let post = match params.get("item_uuid") {
         Some(uuid) => match blog::Post::find_by_uuid(&uuid).await {
             Ok(post) => Some(post),