huskies: merge 927

server/src/chat/transport/whatsapp/format.rs

@@ -1,4 +1,5 @@
 //! WhatsApp message formatting — Markdown-to-WhatsApp conversion and message chunking.
+use crate::chat::util::truncate_at_char_boundary;
 use regex::Regex;
 use std::sync::LazyLock;
 
@@ -24,13 +25,13 @@ pub fn chunk_for_whatsapp(text: &str) -> Vec<String> {
         }
 
         // Find the best split point within the limit.
-        let window = &remaining[..WHATSAPP_MAX_MESSAGE_LEN];
+        let window = truncate_at_char_boundary(remaining, WHATSAPP_MAX_MESSAGE_LEN);
 
         // Prefer paragraph boundary.
         let split_pos = window
             .rfind("\n\n")
             .or_else(|| window.rfind('\n'))
-            .unwrap_or(WHATSAPP_MAX_MESSAGE_LEN);
+            .unwrap_or(window.len());
 
         let (chunk, rest) = remaining.split_at(split_pos);
         let chunk = chunk.trim();