test: correct the SYNC_WAIT_MS comment and guard six 202 branches (#656)

The comment added in #652 was wrong. It said SYNC_WAIT_MS=0 drives every tool through its 202 path; it does the opposite. BullMQ arms its timer under `if (ttl)`, so 0 is falsy, waitUntilFinished waits forever and every route answers 200, matching the repo-wide convention that 0 means unlimited. A small positive value such as 1 is what forces the async path.

That error mattered: the local validation claimed for #652 exercised the synchronous path throughout and never reached settleAsyncFallback. Redone with SYNC_WAIT_MS=1, it surfaced six specs whose status gate accepts 202 but whose else branch then demands an error body a 202 never carries, a latent flake on a slow runner.

Each now settles the job first. Under a forced 1ms window the 'expected undefined to be defined' failures drop from 55 to 0, and all 1183 tests still pass on the normal 30s window. Per-shard totals unchanged at 9903 tests, 9435 passed, 468 skipped.

Specs asserting a bare 200 without listing 202 are deliberately untouched: they own the synchronous contract.

tests/integration/generated/format-matrix-3.test.ts

@@ -60,6 +60,7 @@ describe("Multipage TIFF handling", () => {
       // Multipage TIFF should either succeed or return a clean error
       expect([200, 202, 400, 422]).toContain(res.statusCode);
 
+      if (await settleAsyncFallback(res)) return;
       if (res.statusCode === 200) {
         const body = JSON.parse(res.body);