Add ConversationEventMap and event-name mapping

[kraenhansen]

Summary

• Create packages/client/src/events.ts combining generated events (GeneratedEventMap) with hand-written internal and extra events into a unified ConversationEventMap
• Move Callbacks, CALLBACK_KEYS from types.ts to events.ts and add CALLBACK_KEY_TO_EVENT_NAME mapping table
• Override vad-score in ConversationEventMap for backward-compatible { vadScore } payload shape
• Export ConversationEventMap from the client package

Part of #738 (PR 3/6).

Test plan

• pnpm turbo build check-types lint passes for all packages (30/30 tasks)
• Downstream packages (@elevenlabs/react, @elevenlabs/react-native, widget packages) build successfully
• No import cycle introduced (client → types for generated types only)

🤖 Generated with Claude Code

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Note

Low Risk
Primarily TypeScript type/export reshaping with a new mapping constant; runtime behavior is largely unchanged aside from consumers relying on old import locations.

Overview
Introduces a new events.ts module that defines a unified ConversationEventMap by combining generated wire events with internal/extra conversation events, including a backward-compatible override for the vad-score payload shape.

Moves Callbacks and CALLBACK_KEYS out of types.ts into events.ts, and adds a CALLBACK_KEY_TO_EVENT_NAME table to map callback property names (e.g. onMCPToolCall) to their corresponding emitted event names.

Updates exports so BaseConversation/package index.ts now re-export Callbacks, CALLBACK_KEYS, and the new ConversationEventMap from events.ts, and trims types.ts to core shared types only.

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