twitterbridge: one poller, per-webhook seen sets, fxtwitter links, outage DM

The RSSHub feed isn't strictly chronological, so 'post everything above the
last guid' could skip tweets. Now a single poller fans out to both webhooks,
each remembering posted guids (data/twitter_seen.json, atomic writes): new
tweets anywhere above the oldest known one are posted oldest-first, old tweets
sliding in after a deletion are ignored, failed posts retry next poll and
Discord 429s are honoured. Links go out as fxtwitter.com for real embeds.
The owner gets a DM after 90 min of broken feed and again on recovery.
Night polling is now 1-2 h.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

twitterbridge/leaks_cmd.py

@@ -3,6 +3,8 @@ import aiohttp
 import feedparser
 from discord.ext import commands
 
+from twitterbridge.rss import embed_link
+
 REQUEST_TIMEOUT = 15
 
 
@@ -50,10 +52,7 @@ class TwitterLeaks(commands.Cog):
 
         response = "**Latest 5 Leaks:**\n"
         for entry in entries[:5]:
-            link = entry.get('link', '')
-            if 'nitter.net' in link:
-                link = link.replace('nitter.net', 'twitter.com').replace('#m', '')
-            response += f'\n{link}\n'
+            response += f"\n{embed_link(entry.get('link', ''))}\n"
 
         await ctx.reply(response[:2000])