feat(discord): Core Prisms, Lenses and Beams Implementation (#57 - $2000)

[sirius-016]

Summary

Complete Discord core prisms, lenses, and beams for Issue #57 ($2000).

Components

Lenses (6) - Data Reading

• GetMessages, GetChannel, GetGuild, GetMember, ListChannels, GetBans

Prisms (16) - Actions

Message Management: SendMessage, EditMessage, DeleteMessage, BulkDeleteMessages, AddReaction
Channel Management: CreateChannel, EditChannel, DeleteChannel
Moderation: TimeoutMember, BanMember, UnbanMember, KickMember, AssignRole
Threads & Events: CreateThread, CreateScheduledEvent, CancelScheduledEvent

Beams (2) - Workflows

• ModerationWorkflow (auto-moderation with escalation)
• ChannelSetupWorkflow (one-step channel creation)

Tests & Docs

• 8 test files, Livebook guide, Benchee benchmarks

Acceptance Criteria

• MessageManagementPrism ($600)
• ChannelManagement ($500)
• ModerationPrism ($500)
• EventHandling ($400)
• Rate limiting, error handling, state management
• Unit tests, documentation, examples

30 files total.

Closes #57