- Use string.IsNullOrWhiteSpace (not IsNullOrEmpty) when normalizing the constructor sourceName, so callers passing whitespace-only strings still land on OpenTelemetryConsts.DefaultSourceName instead of an unsubscribed ActivitySource.
- Fix the misleading pragma comment on the 2-arg ctor delegating call: auto-wiring is the new default, it does not preserve the original (pre-PR) behavior.
- Expand the GetRunOptionsWithChatClientWiring XML doc to spell out that a base AgentRunOptions (not ChatClientAgentRunOptions) is also accepted: it is converted to ChatClientAgentRunOptions with the auto-wire factory installed and base properties copied.
- Tests: extend the source-name normalization Theory with whitespace cases (' ' and '\t'); add end-to-end coverage for plain AgentRunOptions over a real ChatClientAgent (sync + streaming) asserting the inner chat client is invoked and both invoke_agent + chat spans are emitted.