Python(feat): resume incomplete test report upload - #745

import-test-result-log <log> now finishes an interrupted upload instead of creating a second report.

Every upload records what reached the server in a tracking sidecar beside the log (<log>.jsonl.tracking). A re-run reuses the report the earlier attempt created and sends only the missing entries; a fully uploaded log is a no-op. Resuming needs that report to still exist, so if it was deleted or the sidecar came from another environment the command fails and points at --new-report.

--new-report, and import_log_file(..., new_report=True), abandons the partial upload and creates a new report. The old sidecar moves to .tracking.bak so the abandoned report's ID stays recoverable.

import-test-result-log is now two modes, and the help text, docstrings, and guide all name the same two:

The third mode is gone from the public command. --incremental followed a log while the run writing it was still going, which only the plugin's background worker has a reason to do, and it ticked until stdin closed rather than stopping at the end of the log, so it was never a way to finish an interrupted upload and appeared to hang when run by hand. That mode now runs as an internal worker module the plugin spawns for itself, reachable by no flag. Anything passing --incremental by hand should drop it, since the default path resumes.

The two entry points share their connection arguments, client construction, and failure hint through one internal module rather than a copy each, and the worker no longer imports the report-context chain at startup, which was roughly 190 ms of pandas it needs only on the failure path.

16 new tests cover batch progress recording, resume through both paths, partially created batched measurement lines, the completed no-op, --new-report, the error paths, and the worker's follow mode, where an idle tick stays silent and never marks a growing log complete. 214 tests pass across the replay, session-artifact, report-context, and plugin suites. Also checked end to end against a plugin-produced offline log: an upload interrupted partway resumes to the same 63 entities as a clean run, with no duplicate report.