agentic_loop: derive tool calls from response_object.output for terminal-event reconciliation

[leseb]

Context

Issue #26 comment #2 notes that when stream_events lands, state.tool_calls can be stale relative to response_object after a terminal event (response.completed). The terminal event overwrites response_object with the authoritative payload, but does not rebuild state.tool_calls — so tool_calls reflects incrementally accumulated deltas while response_object.output reflects the terminal truth.

Currently tool_dispatch reads exclusively from state.tool_calls via std::mem::take(&mut state.tool_calls).

Proposed fix

Derive tool calls from response_object["output"] at dispatch time (option 1 from the comment — single source of truth). Fall back to tool_calls when response_object has no output (backward compat for pre-stream_events paths).

Blocked by

• Filter 6: stream_events #25 (stream_events) — until terminal events populate response_object, the fallback path is the only one exercised

References

• Filter 7: agentic_loop #26 comment Add CI workflow suite for AI filters repo #2
• Part of Epic: Responses API and Agentic Loop Orchestration #93