## What changed
- Include the complete upstream `response.usage` object in
`ResponseUsageMetadata.metadata` while retaining the existing `amount` field.
- Expose the metadata through `rawResponse/completed` notifications and update
the generated JSON and TypeScript schemas.
## Testing
- Cover SSE, WebSocket, turn, and compaction completion paths.
GitOrigin-RevId: 6d79b1b4c92ac11abf43ec98f380b4868288a701
## What changed
- Parse optional `usage_metadata.amount` values from Responses API completion events without converting their string representation.
- Propagate the metadata through SSE and WebSocket streams, regular turns, and remote compaction.
- Add `usageMetadata` to the app-server `rawResponse/completed` notification and its generated schemas.
## Testing
- Cover missing, null, zero, and high-precision amounts, including completion events emitted during compaction.
GitOrigin-RevId: b16d81e8350eab0dc7ff613d0dc9dbed73041713
sayan-oai