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* ci: cancel superseded eval runs; relax LLM-judge clarity bar to 3

test/egress-receipt-wiring.test.ts

@@ -149,6 +149,8 @@ const SCANNER_EXEMPT: Record<string, string> = {
     'served-page JS talking to its own loopback server (same-origin relative fetch)',
   'design/src/compare.ts':
     'served-page JS talking to its own loopback server (relative ./api fetch)',
+  'scripts/ubicloud':
+    'developer-invoked test infrastructure: Ubicloud API calls (VM create/show/destroy) with the developer\'s own token, the checkout streamed over SSH to that developer\'s own ephemeral VM, and toolchain downloads run on the VM; no installed-gstack user state is sent',
   // Skill prose templates: these render agent-executed instructions (the
   // agent runs git in the USER\'S repo at the user\'s direction), they are
   // not gstack binaries. Includes the preamble-generated brain-sync block —