Add a real file-upload path so PLC projects (and other blob artifacts:
firmware images, source archives, mobile packages) can be delivered to
the agent instead of referencing a local path.
- agent: POST /api/v1/targets/{id}/artifacts/upload (axum multipart);
stores bytes under {artifact_store_base_path}/uploads/{id}/... and
$push-es the artifact (with stored_path + size_bytes) onto the target.
- dashboard: upload_target_artifact server fn (reqwest multipart) + wizard
file input for blob artifact kinds, with a PLC format selector.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
