Add summarize_partial_history: a one-shot writer-model pass that turns an
annotated transcript (tool calls with their args, so a fetch's URL or a
search's query stays attached to its result, plus results and interim
notes) into a proper footnote-style findings dump, instead of the flat
concatenation partial_findings_from_history produces on its own.
It's wired in as the MaxTurnsError recovery path in gather_findings, but
partial_findings_from_history stays as the fallback for an empty transcript
or if the summarizer call itself fails — the one guaranteed recovery path
shouldn't have a second turn-budget/model failure as a single point of
failure.
Observability: instrumented with the same #[tracing::instrument(fields(
gen_ai.agent.name = ...))] + spinner pattern as the researcher/reviewer/
writer phases, with info!/warn! events on success, empty-transcript
skip, and summarizer failure.
Also: cargo fmt across the crate (unrelated formatting drift had
accumulated), and adds unit tests for the new transcript_lines /
annotated_transcript_from_history helpers.
21030462b1