fix: FriendliAI 403 credit exhaustion misclassified as auth_error (#13040)

* Add new error signal for depleted credits

* chore: add changelog fragment for #13040 FriendliAI credit-exhaustion 403 fix

* test(accountFallback): add FriendliAI credit-exhaustion 403 body test (#13040)

---------

Co-authored-by: fesshompa <fesshompa@yahoo.com>

changelog.d/fixes/13040-friendliai-credit-exhaustion-403.md

@@ -0,0 +1 @@
+- **fix(friendliai):** FriendliAI's free-tier credit-exhaustion 403 (`{"detail":"You've exhausted all your credits..."}`) is now classified as `QUOTA_EXHAUSTED` instead of `AUTH_ERROR`, so omniroute treats it as depleted credits rather than a credential problem ([#13040](https://github.com/diegosouzapw/OmniRoute/pull/13040)) — thanks @turbolego

open-sse/services/accountFallback.ts

@@ -260,6 +260,8 @@ export const CREDITS_EXHAUSTED_SIGNALS = [
   // marked credits_exhausted and keeps being re-selected on every request.
   "insufficient credits",
   "insufficient credit",
+  // FriendliAI 403 when free tier credits are depleted via adaptive rate limits
+  "exhausted all your credits",
 ];
 
 // T11: Signals that indicate OAuth token is invalid/expired (not permanent deactivation)

tests/unit/account-fallback-service.test.ts

@@ -1196,6 +1196,22 @@ test("isCreditsExhausted returns true for actual credits-exhausted signals", ()
   );
 });
 
+test("isCreditsExhausted matches FriendliAI credit-exhaustion 403 body (#13040)", () => {
+  // FriendliAI returns HTTP 403 with body {"detail":"You've exhausted all your
+  // credits..."} when free tier credits are depleted via Adaptive Rate Limits.
+  // Before #13040 this fell through every quota/credits check to the generic
+  // 403 -> AUTH_ERROR fallback; the signal below routes it to QUOTA_EXHAUSTED.
+  assert.equal(isCreditsExhausted("You've exhausted all your credits"), true);
+  assert.equal(
+    isCreditsExhausted('{"detail":"You\'ve exhausted all your credits"}'),
+    true
+  );
+  assert.equal(
+    isCreditsExhausted("exhausted all your credits"),
+    true
+  );
+});
+
 test("CREDITS_EXHAUSTED_SIGNALS no longer contains generic gRPC resource-exhausted patterns", () => {
   // These patterns were removed because they falsely matched Gemini RPM 429 errors
   assert.equal(CREDITS_EXHAUSTED_SIGNALS.includes("resource has been exhausted"), false);