refactor: Improve Discord message chunking based on code review

- Use single regex for emoji conversion (better performance)
- Fix exact-length line bug that could cause blank messages
- Change line length check from > to >= maxLength

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: htilly

lib/discord.js

@@ -258,6 +258,7 @@ async function sendDiscordMessage(channelId, text, options = {}) {
             let discordText = text.replace(/<(https?:\/\/[^|>]+)\|([^>]+)>/g, '[$2]($1)');
 
             // Convert common Slack emoji codes to Unicode emoji for Discord
+            // Use a single regex-based replacement for better performance with large messages
             const emojiMap = {
                 ':notes:': '🎵',
                 ':lock:': '🔒',
@@ -284,9 +285,7 @@ async function sendDiscordMessage(channelId, text, options = {}) {
                 ':exclamation:': '❗',
                 ':sparkles:': '✨'
             };
-            for (const [slackEmoji, unicodeEmoji] of Object.entries(emojiMap)) {
-                discordText = discordText.split(slackEmoji).join(unicodeEmoji);
-            }
+            discordText = discordText.replace(/:[a-z_]+:/g, (match) => emojiMap[match] || match);
 
             // Discord has a 2000 char limit, split into chunks if needed
             // Use 1800 as max to have buffer for edge cases with Unicode
@@ -338,8 +337,8 @@ async function sendDiscordMessage(channelId, text, options = {}) {
                             await new Promise(resolve => setTimeout(resolve, 300));
                         }
 
-                        // Handle oversized single lines
-                        if (line.length > maxLength) {
+                        // Handle oversized or exact-length lines (>= to avoid adding newline that exceeds limit)
+                        if (line.length >= maxLength) {
                             await sendChunkSafe(line);
                             chunkCount++;
                             await new Promise(resolve => setTimeout(resolve, 300));