v1.91.5.0 feat: balanced free-suite shards, test:ubicloud, and faster PR eval lane (#2989)

* v1.91.5.0 feat: balanced free-suite shards, 16-way Linux runs, and bun run test:ubicloud

* chore: regenerate agents digest for v1.91.5.0

* ci: serial flaky retry and flake ledger for the Windows free lane

* ci: cancel superseded eval runs; relax LLM-judge clarity bar to 3

.github/workflows/evals-periodic.yml

@@ -275,9 +275,10 @@ jobs:
   report:
     runs-on: ubicloud-standard-2
     needs: [plan-slices, eval-slices, gate-census]
-    # always(): the report must run (and FAIL) when an executor died — a
-    # missing slice artifact reading as green is the class this lane kills.
-    if: always() && needs.plan-slices.result == 'success'
+    # !cancelled(): the report must run (and FAIL) when an executor died — a
+    # missing slice artifact reading as green is the class this lane kills —
+    # but a cancelled run stops here.
+    if: ${{ !cancelled() && needs.plan-slices.result == 'success' }}
     timeout-minutes: 10
     permissions:
       contents: read