Add compatibility matrix fixture execution

Run package test jobs across every selected provider combination with isolated lane state, released-image canaries, controlled OIDC DNS, and deterministic cleanup.

tests/kind/run-durable-job.sh

@@ -39,10 +39,12 @@ export REMORA_REAL_NERDCTL
   --tag remora-kind-durable:local \
   "$ROOT"
 OWNS_FIXTURE=true
-setup_fixture
+setup_fixture durable
 load_local_image remora-kind-durable:local
-sed "s|@@TEST_IMAGE@@|remora-kind-durable:local|g" \
-  "$TESTBED/durable-job.yaml.in" > "$RUNTIME/durable-job.yaml"
-run_job_manifest "$FIXTURE_NAMESPACE" durable-substrate "$RUNTIME/durable-job.yaml"
+run_job_matrix \
+  durable-substrate \
+  "$TESTBED/durable-job.yaml.in" \
+  remora-kind-durable:local \
+  durable
 SUCCEEDED=true
 printf 'durable substrate package test Job passed\n'