Remove allowedSfxChannels functionality - allow SFX in all channels

- Remove allowedSfxChannels from database schema and all code
- Remove channel checking logic from all SFX commands (!sfx, /sfx, /soundboard)
- Remove /config sfxchannels subcommand
- Update config.json and example to remove channel restrictions
- Simplify SFX system to work in any channel with bot access

Benefits:
- Better user experience - no confusing channel restrictions
- Simpler configuration - fewer settings to manage
- Cleaner codebase - reduced complexity
- Universal access - SFX works anywhere the bot can send messages

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

conf/text_commands

@@ -1,2 +1,3 @@
 f|is for :frog:
 imelly|Didn't know this was a political channel. WTF, you don't have sites where you can vomit that garbage out for the peanut gallery? Not everyone holds your same position. Why do that? Don't assume everyone is a socialist. Knock it off. I didn't join here to listen to your political BS. I am not paying a subscription to listen to you people pontificate about your political hangups with normal people. Unsubscribed, unfollowed. -iMellyGurl
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