feat(otel): carry W3C traceparent via SQS MessageAttributes (ADR-0028)

Implements the babelqueue-core 1.5.0 header seam so traceparent rides the broker
beside the frozen envelope (GR-1), merge-not-clobber + (Redis) bare-value back-
compat; no header falls back to the v0.1 trace_id mapping. Core dep bumped to
1.5.0; package bumped to 1.1.0.

first commit