fix(live-check): findings on resource samples carry resource attributes

[fabiovincenzi]

Problem

Findings on resource-level attributes are emitted (via --emit-otlp-logs) with
none of the source resource's attributes, while findings on span/metric/log
samples correctly carry them.

Sample::resource() returns None for a Sample::Resource: it only returns a
sample's parent resource, and a resource has no parent.

Fix

Make a resource sample its own resource.

The only other callers are sample_log.rs and sample_metric.rs, and both only
ever run on log/metric samples, so this doesn't change anything for them.

Testing

Unit tests covering: a resource sample is its own resource, span samples still
return their parent resource, samples without one still return None, and the
emit path flattens a resource sample's attributes into a finding.
Without the fix these fail with left: None, right: Some("my-test-service").

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: fabiovincenzi / name: Fabio Vincenzi (a18a36d)
• ✅ login: fabiovincenzi / name: fabiovincenzi (03ec5b2)

[opentelemetry-pr-dashboard]

Pull request dashboard status

Waiting on reviewers · refreshed 2026-08-04 14:26 UTC

Review the latest changes.

Status above doesn't look right?

• Just replied or pushed? Anything around or after the refresh time above may not be picked up yet — give it a few minutes.
• Anything look wrong? Report it with what you expected; it helps us improve the dashboard.