- Constructor now throws if resuming with handle that has no sessionId
- Removed fallback chain (sessionId ?? nativeHandle ?? null)
- Removed pendingLocalId - no more random UUID generation on resume
- Added validation after run() - throws if sessionId still null
- resolveHistoryPath() now respects CLAUDE_CONFIG_DIR env var
- Added comprehensive resume test that verifies context preservation
- Fixed test helper to also respect CLAUDE_CONFIG_DIR