ci(chain): stop gating all suites on the performance runner (#7924)

ci(chain): gate the performance lane on its fleet probe (rebase + contract)

Rebased onto latest main; adds the contract-test update that the first
push of this branch missed:

- test_functional_chain: the performance lane now asserts the new
  probe-gated 'if' (prepare success AND performance_ready == online);
  the other nine lanes keep the plain prepare gate; prepare must carry
  the two preflight steps (hard smoke-testing check, pf-testing probe)
  and publish the performance_ready output

Carried over unchanged from the previous push: per-fleet preflight
(prepare hard-fails only on smoke-testing), the pf-testing probe step,
the probe-gated performance lane, and aggregate's --allow-skipped
(permitted skips shrink the evidence set; unpermitted skips still fail
aggregation). Chain contract tests: 27/27 locally.

.github/workflows/rustfs-functional-chain.yml

@@ -46,6 +46,7 @@ jobs:
     timeout-minutes: 10
     outputs:
       manifest: ${{ steps.candidate.outputs.manifest }}
+      performance_ready: ${{ steps.perf_probe.outputs.performance_ready }}
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
         with:
@@ -65,10 +66,25 @@ jobs:
           path: ${{ runner.temp }}/chain-candidate.json
           if-no-files-found: error
 
-      - name: Check shared functional runners before scheduling suites
+      - name: Check shared functional fleet runner before scheduling suites
+        # The nine functional suites run on the smoke-testing fleet; a hard
+        # requirement. The performance lane runs on pf-testing, which is a
+        # separate fleet - probe it without failing the whole chain so an
+        # offline performance runner skips only the performance lane.
         env:
           GH_TOKEN: ${{ secrets.PF_TESTING_GH_TOKEN }}
-        run: python3 scripts/check_functional_runners.py smoke-testing pf-testing
+        run: python3 scripts/check_functional_runners.py smoke-testing
+
+      - name: Probe performance fleet runner
+        id: perf_probe
+        env:
+          GH_TOKEN: ${{ secrets.PF_TESTING_GH_TOKEN }}
+        run: |
+          if python3 scripts/check_functional_runners.py pf-testing; then
+            echo "performance_ready=online" >> "$GITHUB_OUTPUT"
+          else
+            echo "performance_ready=offline" >> "$GITHUB_OUTPUT"
+          fi
 
   upgrade:
     needs: [prepare]
@@ -144,7 +160,7 @@ jobs:
 
   performance:
     needs: [prepare, replication]
-    if: ${{ always() && needs.prepare.result == 'success' }}
+    if: ${{ always() && needs.prepare.result == 'success' && needs.prepare.outputs.performance_ready == 'online' }}
     uses: ./.github/workflows/rustfs-performance-test.yml
     with:
       chain_manifest: ${{ needs.prepare.outputs.manifest }}
@@ -192,6 +208,7 @@ jobs:
           CHAIN_NEEDS: ${{ toJSON(needs) }}
         run: >-
           python3 scripts/functional_chain_evidence.py aggregate
+          --allow-skipped "${{ needs.prepare.outputs.performance_ready == 'online' && '' || 'performance' }}"
           --directory "${RUNNER_TEMP}/chain-evidence"
           --output "${RUNNER_TEMP}/chain-complete.json"
       - name: Upload complete-chain evidence