fix(evidence): split the operator SKIP rationale into its own paragraph

The SKIP line emitted the verdict and the self-install carve-out as a single
Markdown line, so robust-operator.md rendered them as one ~90-word paragraph.
Emit the carve-out as a second paragraph, so the verdict reads on its own and
the reason a live kubeflow-system Trainer is not counted sits beside it rather
than buried at the end of a block.

Wording is unchanged apart from an em-dash to a colon, avoiding two dashes in
what is now a short standalone sentence.

Refs #2223

Signed-off-by: Yuan Chen <yuanchen97@gmail.com>

Author: yuanchen8911

pkg/evidence/cncf/scripts/collect-evidence.sh

@@ -2564,7 +2564,9 @@ collect_operator() {
         collect_operator_kubeflow
     else
         write_section_header "Robust AI Operator"
-        echo "**Result: SKIP (prerequisite absent)** — the recipe/bundle deployed no supported AI operator: no Dynamo operator in \`dynamo-system\`, no NIM operator in \`nvidia-nim\`, and no Kubeflow Trainer in \`kubeflow\`. A Kubeflow Trainer that the performance validator self-installed into \`kubeflow-system\` for the NCCL benchmark is deliberately not counted here — it is torn down at the end of the run and is not part of the deployed bundle." >> "${EVIDENCE_FILE}"
+        echo "**Result: SKIP (prerequisite absent)** — the recipe/bundle deployed no supported AI operator: no Dynamo operator in \`dynamo-system\`, no NIM operator in \`nvidia-nim\`, and no Kubeflow Trainer in \`kubeflow\`." >> "${EVIDENCE_FILE}"
+        echo "" >> "${EVIDENCE_FILE}"
+        echo "A Kubeflow Trainer that the performance validator self-installed into \`kubeflow-system\` for the NCCL benchmark is deliberately not counted here: it is torn down at the end of the run and is not part of the deployed bundle." >> "${EVIDENCE_FILE}"
         log_info "Robust operator evidence collection skipped — no supported operator deployed by the recipe/bundle."
         return
     fi