* refactor: remove the legacy agent-core v1 package
Delete packages/agent-core (v1 engine) and migrate node-sdk fully onto
agent-core-v2:
- node-sdk owns its public contract (error protocol, KimiConfig schema
and file IO, process-global logging facade, telemetry client
interface); event and interaction types re-export from
@moonshot-ai/protocol or agent-core-v2
- createKimiHarness is now the single harness factory, backed by the
v2 client; the v1 SDKRpcClient is deleted
- CLI and vscode run agent-core-v2 unconditionally;
KIMI_CODE_LEGACY_FLAG and useAgentCoreV1 are removed
- the wire.jsonl replay fold moves into agent-core-v2's replayBuilder
(foldWireRecords), and the v2 journal now persists tool-call display
so replay restores diff/todo displays
- TUI engineV2 branches collapse to the v2 path
* test(vscode): retry temp-dir teardown in replay-resume integration test
