[diegosouzapw]

Closes #9315

Root cause: In stream.ts, the providerPayload for the dashboard log was built via buildStreamSummaryFromEvents(providerPayloadCollector.getEvents(), ...), which reconstructs the response from raw captured SSE events. The StructuredSSECollector is head-retaining/tail-dropping with default caps (maxEvents=200/maxBytes=48KB). Once those caps are exceeded, every subsequent event is silently dropped. For reasoning + tool-calling models, a stream easily exceeds these caps, so the "Provider Response" panel in the dashboard was built from only the early chunks — missing final content, reasoning_content, tool_calls, and the real finish_reason.

Fix: Use the same accumulated responseBody for providerPayload that the clientPayload already uses — pass responseBody directly to providerPayloadCollector.build() instead of buildStreamSummaryFromEvents(providerPayloadCollector.getEvents(), ...). This matches the client path and ensures the dashboard shows correct data regardless of stream length.

Two sites changed in stream.ts:

1. Passthrough flush onComplete (line ~2510)
2. Translate flush onComplete (line ~2785)

[hartmark]

Thanks for the fix! We hit the same root cause independently while live-testing #9439 and already closed it there (commit 52671130a) with a slightly broader version: streamPayloadCollector.ts's per-format summary builders were turned into incremental reducers that ingest every chunk as it streams (collector.getSummary()), applied at all 3 onComplete call sites in stream.ts — including the mid-stream failure/error path (~line 2611), which still uses the old buildStreamSummaryFromEvents(getEvents(), ...) reconstruction here and would still show a truncated/stale Provider Response panel for a response that reasons/tool-calls and then errors out mid-stream.

#9315 will close via #9439 instead, so no action needed here — leaving this open for you to close since it's your PR, not mine to close.