feat: add password protection cog for channels

Adds new Discord bot cog enabling password-protected channels.
Includes verification, channel management, whitelist/blacklist,
and admin password recovery features.

pp/__init__.py

@@ -0,0 +1,5 @@
+from .passwdprotect import Passwd
+
+async def setup(bot):
+    cog = Passwd(bot)
+    await bot.add_cog(cog)