fix(ap): wrap outbound Note content in HTML paragraph tags

crates/adapters/activitypub-base/src/service.rs

@@ -28,6 +28,24 @@ use crate::{
     webfinger::webfinger_handler,
 };
 
+fn content_to_html(text: &str) -> String {
+    let escaped = text
+        .replace('&', "&")
+        .replace('<', "&lt;")
+        .replace('>', "&gt;")
+        .replace('"', "&quot;");
+    let paragraphs: Vec<&str> = escaped.split('\n').filter(|s| !s.is_empty()).collect();
+    if paragraphs.is_empty() {
+        format!("<p>{}</p>", escaped)
+    } else {
+        paragraphs
+            .iter()
+            .map(|p| format!("<p>{}</p>", p))
+            .collect::<Vec<_>>()
+            .join("")
+    }
+}
+
 fn thought_note_json(
     thought: &domain::models::thought::Thought,
     local_actor: &crate::actors::DbActor,
@@ -56,7 +74,7 @@ fn thought_note_json(
         "id": ap_id.to_string(),
         "url": ap_id.to_string(),
         "attributedTo": local_actor.ap_id.to_string(),
-        "content": thought.content.as_str(),
+        "content": content_to_html(thought.content.as_str()),
         "published": thought.created_at.to_rfc3339(),
         "to": to,
         "cc": cc,