What Happened
- The PR fixes a correctness bug in google/adk-go where `/api/run` and `/api/run` SSE handlers decoded `RunAgentRequest.StateDelta` but did not persist it, so resumed or contextual runs could execute with unchanged session state. It adds a central `applyStateDeltaIfPresent` path that appends a `system` `state_delta` event through `sessionService.AppendEvent` before invoking the runner, and then uses that merged state in `Get()`, ensuring runtime state now updates as documented.
- The PR fixes a correctness bug in google/adk-go where `/api/run` and `/api/run` SSE handlers decoded `RunAgentRequest.StateDelta` but did not persist it, so resumed or contextual runs could execute with unchanged session state. It adds a central `applyStateDeltaIfPresent` path that appends a `system` `state_delta` event through `sessionService.AppendEvent` before invoking the runner, and then uses that merged state in `Get()`, ensuring runtime state now updates as documented.
- 1 evidence item attached for review.