ci: shorten full release validation critical path (#107894)

* ci(release): parallelize plugin Docker lanes

* test(plugins): expect malformed URL redaction

* ci: start release performance validation concurrently

* docs(agents): guard PR operations after throttling

.github/workflows/full-release-validation.yml

@@ -1248,7 +1248,9 @@ jobs:
     name: Run product performance evidence
     needs: [resolve_target, evidence_reuse]
     if: ${{ always() && needs.resolve_target.result == 'success' && contains(fromJSON('["all","performance"]'), inputs.rerun_group) && needs.evidence_reuse.outputs.reuse != 'true' }}
-    runs-on: ubuntu-24.04
+    # Keep this monitor off the four-slot GitHub-hosted pool so performance starts
+    # with the other child workflows instead of extending the critical path.
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     timeout-minutes: ${{ inputs.release_profile == 'full' && 360 || 120 }}
     outputs:
       run_id: ${{ steps.dispatch.outputs.run_id }}

.github/workflows/plugin-prerelease.yml

@@ -548,7 +548,7 @@ jobs:
       include_release_path_suites: false
       include_openwebui: false
       docker_lanes: ${{ needs.preflight.outputs.plugin_prerelease_docker_lanes }}
-      targeted_docker_lane_group_size: 4
+      targeted_docker_lane_group_size: 2
       allow_unreleased_changelog: true
       include_live_suites: false
       live_models_only: false