All warn/error log calls now use field names the dashboard's decorate()
function recognizes: `code` for the error code pill, `httpStatus` for the
status badge and severity bucket, `url` for the sidebar link, and
`repoId` for the repository link.
Key changes:
- Streamer errors surface code, httpStatus, url, and nested err in Raw tab
- Nested `{ err: serializeError(e) }` replaced with spread pattern so
error fields (name, message, status) appear at the top level
- Raw Error objects in catch blocks now go through serializeError()
- Rate limit, token, and PR 404 warnings include code + httpStatus
- Dashboard stack walker traverses both `cause` and `err` chains
- Dashboard Raw tab renders repoId, filePath, upstream*, err, and cause
- trimRawArg recursively trims stacks in nested err/cause chains
- clampPayload strips heavy nested fields before falling back to
truncated placeholder, preserving flat diagnostic fields
Mongoose treats `gist` as a nested path, not a sub-schema, so
set("gist", payload) mis-casts the inner subdoc arrays and fails
validation with 'Cast to [string] failed' at gist.files.0. Set each
subpath individually so the files/comments arrays cast correctly.
tdurieux