Maps ACP session/update notifications to AgentRuntime callbacks using the
authoritative SDK 0.24.0 vocabulary: agent_message_chunk->onText,
agent_thought_chunk->onThinking, tool_call->onToolStart, tool_call_update
(completed/failed)->onToolEnd correlated by toolCallId, plan as full
replacement. tool-mapping.ts derives display names + normalizes args.
createSession now passes a bridging client handler into connect() so
streamed updates reach the engine callbacks. +24 tests (77 total).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>