feat: add DAVE E2EE voice support

[coderobe]

Summary

Adds DAVE E2EE voice protocol support through ffi discord/libdave bindings. DAVE support is only enabled when the libdave native libraries are found and can be loaded, so it is not a new hard dependency unless bot operators want to use voice features.

For testing on macos, i provide a libdave homebrew cask so you can brew tap coderobe/libdave && brew install libdave and this change should pick it up and enable it automatically.

The path to the libdave shared library can be overridden by setting DISCORDRB_LIBDAVE_PATH, and additional libdave-internal debug log verbosity can be tuned with DISCORDRB_LIBDAVE_LOG_LEVEL (defaults to warning).

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Added

discordrb/voice/dave: DAVE E2EE protocol support

[coderobe]

resolves #448

[Droid00000]

Hey, thank you for the PR. After some more testing, I've found a few issues. It may be worth noting that I'm on MacOS, and unsure if any of these issues are platform specific. In essence:

1. Whenever someone joins or leaves the voice channel, the errors listed below occur
2. You cannot hear any audio from the bot, when playing a file, e.g. VoiceBot#play_file

User Join:

[DEBUG : vws-i @ 2026-05-08 22:27:46.692] DAVE: Processing MLS proposals (499 bytes)
[ERROR : vws-i @ 2026-05-08 22:27:46.693] DAVE: Attempted to verify credential for unrecognized user ID: 673658900435697665
[ERROR : vws-i @ 2026-05-08 22:27:46.693] DAVE: MLS add proposal must be for recognized user
[WARN : vws-i @ 2026-05-08 22:27:46.694] VWS close: DAVE MLS failure from ValidateProposalMessage: Unexpected user ID in add proposal
[DEBUG : vws-i @ 2026-05-08 22:27:46.701] Received VWS binary opcode 30 (958 bytes)
[DEBUG : vws-i @ 2026-05-08 22:27:46.701] DAVE: Processing MLS welcome for transition 0
[ERROR : vws-i @ 2026-05-08 22:27:46.703] DAVE: Attempted to verify credential for unrecognized user ID: 673658900435697665
[ERROR : vws-i @ 2026-05-08 22:27:46.703] DAVE: MLS welcome lists unrecognized user ID
[DEBUG : vws-i @ 2026-05-08 22:27:46.703] DAVE: Transition 0 is ready
[DEBUG : vws-i @ 2026-05-08 22:27:46.703] Sending voice opcode 23 with data: {transition_id: 0}
#<Thread:0x0000000123bcc270 core.rb:60 run> terminated with exception (report_on_exception is true):
/Users/qs/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/bundler/gems/discordrb-dave-0a7c89b4be88/lib/discordrb/voice/network.rb:440:in 'Discordrb::Voice::VoiceWS#ready_for_media?': RuntimeError (RuntimeError)
        from /Users/qs/.rbenv/versions/4.0.1/lib/ruby/gems/4.0.0/bundler/gems/discordrb-dave-0a7c89b4be88/lib/discordrb/voice/network.rb:429:in 'Discordrb::Voice::VoiceWS#connect'
        from core.rb:60:in 'block in Discordrb::Voice::VoiceBot#initialize'

User Leave

[DEBUG : vws-i @ 2026-05-08 22:28:22.635] Received VWS message! {"seq":8,"op":13,"d":{"user_id":"673658900435697665"}}
[DEBUG : vws-i @ 2026-05-08 22:28:22.636] Received VWS message! {"seq":9,"op":24,"d":{"protocol_version":1,"epoch":1}}
[DEBUG : vws-i @ 2026-05-08 22:28:22.636] DAVE: Preparing epoch 1 for protocol version 1
[DEBUG : vws-i @ 2026-05-08 22:28:22.638] DAVE: Sending MLS key package
[DEBUG : vws-i @ 2026-05-08 22:28:22.639] Sending voice binary opcode 26 (390 bytes)
[DEBUG : vws-i @ 2026-05-08 22:28:22.642] Received VWS message! {"seq":10,"op":21,"d":{"transition_id":0,"protocol_version":1}}
[DEBUG : vws-i @ 2026-05-08 22:28:22.642] DAVE: Preparing transition 0 for protocol version 1
[WARN : vws-i @ 2026-05-08 22:28:22.644] VWS close: Failed to create DAVE key ratchet for user 1268769703027933235

[coderobe]

I get the user leave warn on close occasionally, although not always. Haven't investigated, but it's not fatal. The other issue i can't reproduce. Audio works fine for me - I have been using my branch for multiple sound bots, although largely with short soundbites.