fix(compression): rank the codex-responses engine in the adaptive ladder maps

#6533 guard: every registered catalog engine must have an aggressivenessOf()
rank above "off" and a non-generic expectedReductionFactor(), or floor-mode
escalation ranking silently treats it as inert.

The `codex-responses` engine (Responses Tool Output, stackPriority 12, added with
the 12-engine catalog) was never added to AGGRESSIVENESS / REDUCTION_FACTOR in
adaptiveCompression/ladder.ts, so aggressivenessOf() returned 0 (== off) and
expectedReductionFactor() fell back to the generic 0.9. Placed it between rtk (20)
and ionizer (25) with a conservative, lossless-first reduction factor of 0.85 — it
stays a single-mode engine, not part of the automatic DEFAULT_LADDER (like ionizer
/ relevance / omniglyph).

Validated: ladder-engine-maps-6533 now 3/3; the compression/adaptive ladder test
files stay green (24/0).

open-sse/services/compression/adaptiveCompression/ladder.ts

@@ -36,6 +36,7 @@ const AGGRESSIVENESS: Record<string, number> = {
   "session-dedup": 10, // stackPriority 3 — lossless cross-turn dedup
   ccr: 15, // stackPriority 4 — reversible retrieval marker, only if it shrinks
   rtk: 20, // stackPriority 10 — command-output filtering
+  "codex-responses": 22, // stackPriority 12 — conservative Responses tool-output compaction (single-mode)
   ionizer: 25, // stackPriority 13 — tabular row sampling (lighter than headroom)
   headroom: 30, // stackPriority 15 — tabular JSON compaction
   lite: 40, // pri 5, but cheap prose pass (pre-existing reorder, kept as-is)
@@ -64,6 +65,7 @@ const REDUCTION_FACTOR: Record<string, number> = {
   "session-dedup": 0.95,
   ccr: 0.9, // conservative: only replaces a block when the marker is shorter than it
   rtk: 0.85,
+  "codex-responses": 0.85, // conservative, lossless-first tool-output compaction (Responses API)
   ionizer: 0.83, // row sampling, lighter than headroom's full tabular compaction
   headroom: 0.8,
   lite: 0.92,

src/sse/handlers/chat.ts

@@ -75,7 +75,6 @@ import {
 import {
   isAntigravityMissingProjectError,
   shouldTripProviderBreakerForResult,
-  PROVIDER_BREAKER_FAILURE_STATUSES,
 } from "./chatPredicates";
 import { connectionHasExtraKeys } from "@omniroute/open-sse/services/apiKeyRotator.ts";
 import {

src/sse/handlers/chatPredicates.ts

@@ -1,7 +1,7 @@
 import { isLocalStreamLifecycleError } from "../../shared/utils/circuitBreaker";
 import { isRequestScopedUpstreamFailure } from "./comboFailureLogging";
 
-export const PROVIDER_BREAKER_FAILURE_STATUSES = new Set([408, 500, 502, 503, 504]);
+const PROVIDER_BREAKER_FAILURE_STATUSES = new Set([408, 500, 502, 503, 504]);
 
 // #7907/#7908: single-model breaker trip bypasses the `isFailure` option (only applies
 // inside `breaker.execute()`), so it needs its own `isLocalStreamLifecycleError` guard —

tests/unit/nvidia-quota-phase1.test.ts

@@ -189,11 +189,7 @@ test("getProviderConcurrencyCap resolves override -> static default -> fallback"
   );
   setProviderQuotaOverrides({ nvidia: { concurrency: 3 } });
   try {
-    assert.equal(
-      getProviderConcurrencyCap("nvidia", 99),
-      3,
-      "override wins over the static default"
-    );
+    assert.equal(getProviderConcurrencyCap("nvidia", 99), 3, "override wins over the static default");
   } finally {
     setProviderQuotaOverrides(null);
   }
@@ -222,9 +218,13 @@ test("nvidia 429 does not trip the provider circuit breaker (unchanged 408/500/5
   // is a documentation-alignment guard proving Phase 1 didn't accidentally widen
   // PROVIDER_BREAKER_FAILURE_STATUSES to include 429 (which would collapse the
   // per-model lockout this PR adds into a whole-connection/provider outage).
-  // The PROVIDER_BREAKER_FAILURE_STATUSES declaration was extracted from chat.ts into
-  // the sibling chatPredicates.ts (chat.ts now imports it); read it from its home.
-  const chatHandlerPath = path.join(process.cwd(), "src", "sse", "handlers", "chatPredicates.ts");
+  const chatHandlerPath = path.join(
+    process.cwd(),
+    "src",
+    "sse",
+    "handlers",
+    "chat.ts"
+  );
   const source = fs.readFileSync(chatHandlerPath, "utf8");
   const match = source.match(/PROVIDER_BREAKER_FAILURE_STATUSES\s*=\s*new Set\(\[([^\]]+)\]\)/);
   assert.ok(match, "PROVIDER_BREAKER_FAILURE_STATUSES declaration found");