[renkun-ken]

Typing sample_result <- dt[, lapply(.SD, function())] while package metadata is pending can send an empty callee name to the navigation index. The resulting error escapes the queued request readiness check and stops the server.

Skip S3 call lookup when the detected call has no callee, including function and control-flow headers. Return an internal error for an unexpected queued readiness failure so later requests can still be served. Add regressions for completion, hover, signature help, and queue recovery.

Testing

• Provider readiness, S3 dispatch, member providers, completion, signature, server core, index policy, and source readiness tests passed. Two optional S3 tests were skipped because datawizard is not installed.
• Installed the package into a temporary library and verified completion, signature help, and hover against a live language-server process, followed by a successful signature request.