tgbridge: rework both directions — avatars, stickers, replies, edits

fixes that were dropping messages:
- d->tg sent parse_mode=Markdown with an unescaped body, so any message
  with a stray * _ ` or [ got a 400 from telegram and vanished. now html
  with proper escaping + a plain-text retry
- no allowed_mentions on webhook posts, so telegram could @everyone
- forwarder.start() ran from on_ready, which fires again on every gateway
  reconnect -> second poller on the same token -> 409s and dupes
- document.mime_type is nullable and was called directly
- sticker finally block hit UnboundLocalError when mkstemp raised
- ffmpeg timeouts leaked temp files and orphaned the process

stickers, per format instead of one blanket gif convert:
- static .webp now passes through (the gif convert crushed 228 alpha
  levels to 2 and made the file 4x bigger)
- video .webm -> animated webp, keeps 8-bit alpha, ~7x smaller than gif.
  needs -c:v libvpx-vp9 before -i or ffmpeg silently drops the alpha
- .tgs is gzipped lottie, ffmpeg exits 183 on it and we were uploading
  the raw file. renders via optional lottie lib, else thumbnail + emoji

added: telegram profile photos as webhook avatars (re-hosted in a private
channel, AVATAR_CACHE_CHANNEL_ID), reply threading both ways, edit sync
both ways, delete sync d->tg, album batching, voice/poll/location/contact/
dice/forward attribution, utf-16-safe entity conversion, mention and custom
emoji resolution, message splitting instead of truncation, shared aiohttp
session with 429 backoff, route discovery from env, !bridge status

main.py just loads the extension now; routes come from credentials.env

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01RXrxDFpyq3VjvxWGuW3CZe

main.py

@@ -5,9 +5,6 @@ import os
 import logging
 import asyncio
 
-from tgbridge.forwarder import TelegramForwarder
-from tgbridge.discord_to_telegram import DiscordToTelegramForwarder
-
 # from twitterbridge.rss import TwitterRSSForwarder
 
 load_dotenv('credentials.env')
@@ -18,19 +15,8 @@ intents.members = True
 
 bot = commands.Bot(command_prefix='!', intents=intents, help_command=None)
 
-# Telegram → Discord
-forwarder = TelegramForwarder(token=os.getenv('TELEGRAM_BOT_TOKEN'))
-if os.getenv('TELEGRAM_GROUP_ID') and os.getenv('DISCORD_WEBHOOK_URL'):
-    forwarder.add_route(int(os.getenv('TELEGRAM_GROUP_ID')), os.getenv('DISCORD_WEBHOOK_URL'))
-if os.getenv('TELEGRAM_GROUP_ID_SHITPOST') and os.getenv('DISCORD_WEBHOOK_URL_SHITPOST'):
-    forwarder.add_route(int(os.getenv('TELEGRAM_GROUP_ID_SHITPOST')), os.getenv('DISCORD_WEBHOOK_URL_SHITPOST'))
-
-# Discord → Telegram (reverse bridge)
-d_to_tg = DiscordToTelegramForwarder(bot=bot, tg_token=os.getenv('TELEGRAM_BOT_TOKEN'))
-if os.getenv('DISCORD_CHANNEL_ID') and os.getenv('TELEGRAM_GROUP_ID'):
-    d_to_tg.add_route(int(os.getenv('DISCORD_CHANNEL_ID')), int(os.getenv('TELEGRAM_GROUP_ID')))
-if os.getenv('DISCORD_CHANNEL_ID_SHITPOST') and os.getenv('TELEGRAM_GROUP_ID_SHITPOST'):
-    d_to_tg.add_route(int(os.getenv('DISCORD_CHANNEL_ID_SHITPOST')), int(os.getenv('TELEGRAM_GROUP_ID_SHITPOST')))
+# The Telegram bridge discovers its own routes from credentials.env and
+# starts polling when the extension loads — see tgbridge/config.py.
 
 # twitter = TwitterRSSForwarder(
 #     webhook_url=os.getenv('TWITTER_DISCORD_WEBHOOK'),
@@ -44,7 +30,6 @@ if os.getenv('DISCORD_CHANNEL_ID_SHITPOST') and os.getenv('TELEGRAM_GROUP_ID_SHI
 @bot.event
 async def on_ready():
     print(f'[+] {bot.user} is online!')
-    asyncio.create_task(forwarder.start())
     # asyncio.create_task(twitter.start())
     # asyncio.create_task(twitter_mao.start())
     # Clear stale global slash commands
@@ -55,7 +40,7 @@ async def on_ready():
 
 async def main():
     async with bot:
-        await bot.add_cog(d_to_tg)
+        await bot.load_extension('tgbridge')
         await bot.load_extension('cogs.general')
         await bot.load_extension('cogs.chance')
         await bot.load_extension('cogs.gifs')
@@ -80,7 +65,9 @@ async def main():
         try:
             await bot.start(os.getenv('DISCORD_TOKEN'))
         finally:
-            await forwarder.stop()
+            # bot.close() unloads extensions, so tgbridge.teardown stops the
+            # Telegram poller and closes its aiohttp session for us
+            pass
             # twitter.stop()
             # twitter_mao.stop()
             # await twitter.close()