[codex] add DM follow-ups

[danjdewhurst]

Summary

Implements the direct-message follow-up backlog in four commits:

• add user blocking with server-side DM send/history gating
• add DM typing indicators over the WebSocket protocol
• add read receipts, unread counts, and friend-list unread badges
• add sender-owned DM editing and deletion with realtime update events

Impact

Players can now block friends from DM flows, see typing state in open DM conversations, get unread badges for unseen DMs, mark messages read with receipts, and edit or delete their own sent DMs. The server persists the new DM state through Drizzle migrations 0011 through 0013.

Validation

• bun run typecheck
• bun run lint
• bun test
• bun run test:coverage
• bun run coverage:check

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