arXiv:2610.35591v1 Announce Type: new Abstract: Edge-centric IoT systems are increasingly evaluated through sensor values or platform features, yet the telemetry pipeline itself, the sequence of sensing, serialization, message mediation, ingestion, and persistence, is rarely released as a measurable object. This limits reproducible benchmarking of timeliness, provenance, and operational cost, especially in early-stage IoT design where real deployments and high-quality open data are often unavailable. I present a measurement-first edge IoT testbed and dataset that elevate timeliness, provenance, and energy to first-class telemetry dimensions. The testbed operationalizes a role-based event-driven architecture with explicit Source-Broker-Aggregator responsibilities and a schema-governed TelemetryMessage envelope (Avro) that embeds correlation identifiers and a uniform, cross-role vocabulary of stage-level timestamps. To trace mediation effects, I extend an MQTT broker (Eclipse Mosquitto) with a plugin that annotates messages with high-precision ingress/egress timestamps. I release the dataset in a dual representation: (i) replayable raw events as compressed Avro streams and (ii) analysis-ready long-format Parquet tables partitioned for efficient query and benchmarking, generated by a deterministic raw-to-tabular transformation pipeline. The contribution is an integrated engineering artifact and dataset built from established components. The demonstration describes one deployment through latency summaries, measurement-context distributions, and energy aggregates; it does not establish a new attribution method or a controlled performance benchmark. By co-releasing heterogeneous telemetry with pipeline timing and energy signals in both replayable and queryable forms, the artifact provides a basis for reproducible exploratory analysis and subsequent benchmarking studies.