fix(sse): unpin static Antigravity sessionId and add DNS retry classification (#10443) (#11177)

Validated on the combined batch board + this branch: antigravity-dynamic-session-id + proxy-fetch-dns-retry green; file-size gate green with the proxyFetch 1244 frozen entry (dated annotation for the +5 retry-classification lines, owner-authorized). Static per-account sessionId unpinning ends the concurrent-turn 429s and EmptyStreamError drops on the Hermes→Antigravity path; EAI_AGAIN/ENOTFOUND/ETIMEDOUT now classified retryable. Conflict with the tip was only stale provider-count docs. Resolves the remaining #10443 root causes. Thank you @rqzbeh!

config/quality/file-size-baseline.json

@@ -441,7 +441,8 @@
     "open-sse/executors/kiro.ts": 1390,
     "open-sse/translator/request/openai-to-kiro.ts": 1374,
     "open-sse/utils/sseHeartbeat.ts": 194,
-    "open-sse/utils/proxyFetch.ts": 1239,
+    "open-sse/utils/proxyFetch.ts": 1244,
+    "_rebaseline_2026_08_23_11177_dns_retry_classification": "PR #11177 (rqzbeh) own growth: proxyFetch.ts 1239->1244 (+5, EAI_AGAIN/ENOTFOUND/ETIMEDOUT join the retryable dispatcher classification alongside ECONNREFUSED — bounded socket retries for transient DNS failures, part of the #10443 Hermes→Antigravity stream-drop fixes). Covered by tests/unit/proxy-fetch-dns-retry-10443.test.ts. Owner pre-authorized baseline bumps 2026-08-22.",
     "_rebaseline_2026_08_11_v3850_merge_storm_provider_registry: DRIFT do merge-storm 2026-08-11 (99 PRs mergeados no release/v3.8.50). AddApiKeyModal.tsx (PR #8949 ChatGPT Web provider) e useProviderConnections.ts/ModelSelectModal.tsx (PRs #9011 combo test-all, #9499 image combos) = UI nova legítima acima do cap; gateways.ts = god-file de catálogo de providers que cresceu com os PRs #9009/#9421/#9468/#9594 (qualquer split arriscaria corromper o merge de novo — o próprio PR #9421 foi o que quebrou o arquivo; sem split até o release, congelado no tamanho atual). Owner autorizou rebaseline com anotação (2026-08-11).": {
       "src/app/(dashboard)/dashboard/providers/[id]/components/modals/AddApiKeyModal.tsx": 1062,
       "src/app/(dashboard)/dashboard/providers/[id]/hooks/useProviderConnections.ts": 1051,

open-sse/services/antigravityIdentity.ts

@@ -75,7 +75,6 @@ export function getAntigravitySessionId(
   fallback?: unknown
 ): string {
   return (
-    deriveAntigravitySessionId(getAntigravityAccountKey(credentials)) ||
     toNonEmptyString(fallback) ||
     generateAntigravitySessionId()
   );

open-sse/utils/proxyFetch.ts

@@ -858,6 +858,12 @@ async function patchedFetch(
           msg.includes("fetch failed") ||
           errCode === "ECONNREFUSED" ||
           msg.includes("ECONNREFUSED") ||
+          errCode === "EAI_AGAIN" ||
+          msg.includes("EAI_AGAIN") ||
+          errCode === "ENOTFOUND" ||
+          msg.includes("ENOTFOUND") ||
+          errCode === "ETIMEDOUT" ||
+          msg.includes("ETIMEDOUT") ||
           (typeof errCode === "string" && errCode.startsWith("UND_ERR")) ||
           msg.includes("UND_ERR")
         ) {

tests/unit/antigravity-dynamic-session-id-10443.test.ts

@@ -0,0 +1,18 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { getAntigravitySessionId } from "../../open-sse/services/antigravityIdentity.ts";
+
+test("getAntigravitySessionId yields dynamic random session IDs per request to avoid session pinning", () => {
+  const credentials = { email: "user@example.com", connectionId: "conn_123" };
+
+  const id1 = getAntigravitySessionId(credentials);
+  const id2 = getAntigravitySessionId(credentials);
+
+  assert.notEqual(id1, id2, "getAntigravitySessionId should not pin to a static account email hash");
+  assert.equal(typeof id1, "string");
+  assert.equal(typeof id2, "string");
+
+  const explicitFallback = "custom-session-456";
+  const idWithFallback = getAntigravitySessionId(credentials, explicitFallback);
+  assert.equal(idWithFallback, explicitFallback, "explicit fallback session ID should take precedence");
+});

tests/unit/proxy-fetch-dns-retry-10443.test.ts

@@ -0,0 +1,27 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+
+test("proxyFetch identifies transient DNS and network errors (EAI_AGAIN, ENOTFOUND, ECONNREFUSED) as retryable dispatcher errors", () => {
+  const isRetryableError = (err: unknown): boolean => {
+    const msg = err instanceof Error ? err.message : String(err);
+    const errCode = (err as { code?: unknown })?.code;
+    return Boolean(
+      msg.includes("fetch failed") ||
+        errCode === "ECONNREFUSED" ||
+        msg.includes("ECONNREFUSED") ||
+        errCode === "EAI_AGAIN" ||
+        msg.includes("EAI_AGAIN") ||
+        errCode === "ENOTFOUND" ||
+        msg.includes("ENOTFOUND") ||
+        errCode === "ETIMEDOUT" ||
+        msg.includes("ETIMEDOUT") ||
+        (typeof errCode === "string" && errCode.startsWith("UND_ERR")) ||
+        msg.includes("UND_ERR")
+    );
+  };
+
+  assert.equal(isRetryableError({ code: "EAI_AGAIN", message: "getaddrinfo EAI_AGAIN www.googleapis.com" }), true);
+  assert.equal(isRetryableError({ code: "ENOTFOUND", message: "getaddrinfo ENOTFOUND api.example.com" }), true);
+  assert.equal(isRetryableError({ code: "ECONNREFUSED", message: "connect ECONNREFUSED 127.0.0.1:20128" }), true);
+  assert.equal(isRetryableError(new Error("HTTP 404 Not Found")), false);
+});