Pass the tool contract's `returnsTargetContent` to
`toRecordedPartialErrorToolResult` in the shared Evidence handler, matching
the Electron call site.
The call site that records a retained partial observation was added without
the argument required by the untrusted target-content framing, so the
delivery neither marked the result nor counted the provenance marker in its
wire budget. The type gate failed on main with
`contractToolHandler.ts(69,38): error TS2554`, which also blocked every
compiled boundary test lane.
