feat: add otel resource and instrumentation scope attributes to traces

[svencowart]

Changes

• introduce otlp/resource module with detect_resource() that collects host.name, host.id, host.ip, telemetry.distro.*, k8s.node.uid, k8s.node.name, k8s.cluster.uid, and k8s.namespace.name at startup
• resolve host.name with priority: k8s internaldns > getaddrinfo ai_canonname > k8s hostname > gethostname() fallback
• collect internalip addresses from k8s node api (all addresses of type
  "InternalIP" from node.status.addresses) with fall back to host_interface_ips() via nix getifaddrs when k8s is unavailable, filtering loopback, point-to-point, and link-local
• cache sdktracer with instrumentation scope set to mermin version, removing per-export provider.tracer() call
• fix metrics_exporter not delegating set_resource to inner exporter, causing resource attributes to never appear in exported spans
• refactor metrics_exporter export to async fn, removing unsafe transmute against a 'static bound that does not exist on the trait
• bump mermin/cargo.toml version in release ci pipeline via sed
• update local k8s dev docs to use colima k3s with a local docker registry

Fixes #481

Type of change

• Bug fix

Testing

Deployed on k8s and without k8s environment and verified the results.

Proof it works

Output without k8s cluster:

Spans
Resource
         ->  host.name=String(Owned("98c4a29c9d1e"))
         ->  telemetry.distro.version=String(Static("0.1.0"))
         ->  telemetry.distro.name=String(Static("mermin"))
         ->  host.id=String(Owned("355568efae014062b277813a9ccd7f54"))
         ->  host.ip=Array(String([Owned("172.17.0.3")]))

Output within k8s cluster:

mermin-c8jj7 mermin Spans
mermin-c8jj7 mermin Resource
mermin-c8jj7 mermin      ->  k8s.cluster.uid=String(Owned("f6200247-39c6-4aa7-948a-c5e56cf6f0a7"))
mermin-c8jj7 mermin      ->  host.name=String(Owned("colima-atlantis"))
mermin-c8jj7 mermin      ->  host.ip=Array(String([Owned("172.17.0.3")]))
mermin-c8jj7 mermin      ->  telemetry.distro.version=String(Static("0.1.0"))
mermin-c8jj7 mermin      ->  telemetry.distro.name=String(Static("mermin"))
mermin-c8jj7 mermin      ->  k8s.node.name=String(Owned("colima-atlantis"))
mermin-c8jj7 mermin      ->  k8s.namespace.name=String(Owned("default"))
mermin-c8jj7 mermin      ->  k8s.node.uid=String(Owned("b1496f8a-62dc-4800-b23f-65a8c89e48ae"))