fix(onboard): recover custom endpoint DNS failures

src/lib/onboard/inference-selection-validation.test.ts

@@ -240,11 +240,7 @@ describe("inference selection validation", () => {
 
   it("routes an unreachable custom endpoint through transport recovery, not a silent loop (#6854)", async () => {
     const probeOpenAiLikeEndpoint = vi.fn(() => ({ ok: true, api: "openai-completions" }));
-    let capturedRecovery: { kind?: string } | undefined;
-    const promptValidationRecovery = vi.fn(async (_label: string, recovery: { kind?: string }) => {
-      capturedRecovery = recovery;
-      return "retry" as const;
-    });
+    const promptValidationRecovery = vi.fn(async () => "retry" as const);
     const error = vi.spyOn(console, "error").mockImplementation(() => {});
     const helpers = createInferenceSelectionValidationHelpers({
       isNonInteractive: () => false,
@@ -258,18 +254,21 @@ describe("inference selection validation", () => {
     });
 
     try {
-      await helpers.validateCustomOpenAiLikeSelection(
+      await expect(
+        helpers.validateCustomOpenAiLikeSelection(
+          "Custom endpoint",
+          "https://example.invalid/v1",
+          "model-a",
+          "COMPATIBLE_API_KEY",
+        ),
+      ).resolves.toEqual({ ok: false, retry: "retry" });
+      expect(probeOpenAiLikeEndpoint).not.toHaveBeenCalled();
+      expect(promptValidationRecovery).toHaveBeenCalledWith(
         "Custom endpoint",
-        "https://example.invalid/v1",
-        "model-a",
+        expect.objectContaining({ kind: "transport", retry: "retry" }),
         "COMPATIBLE_API_KEY",
+        null,
       );
-      // A DNS-unreachable endpoint is a transport failure: the recovery prompt
-      // receives a transport classification (DNS/VPN/URL hint + retry/back/exit),
-      // not the silent selection loop the private-IP path takes.
-      expect(promptValidationRecovery).toHaveBeenCalled();
-      expect(capturedRecovery?.kind).toBe("transport");
-      expect(probeOpenAiLikeEndpoint).not.toHaveBeenCalled();
     } finally {
       error.mockRestore();
     }

src/lib/validation-recovery.test.ts

@@ -19,6 +19,11 @@ describe("validation-recovery helpers", () => {
     expect(
       getTransportRecoveryMessage({ curlStatus: 6, message: "Could not resolve host" }),
     ).toContain("could not resolve");
+    expect(
+      getTransportRecoveryMessage({
+        message: 'cannot resolve endpoint host "example.invalid": getaddrinfo ENOTFOUND',
+      }),
+    ).toContain("Check DNS, VPN, or the endpoint URL");
     expect(
       getTransportRecoveryMessage({ curlStatus: 60, message: "SSL certificate problem" }),
     ).toContain("TLS/certificate");
@@ -44,6 +49,20 @@ describe("validation-recovery helpers", () => {
     });
   });
 
+  it("routes DNS-backed preflight resolution failures through transport recovery (#6854)", () => {
+    const failure = {
+      name: "SSRF preflight",
+      httpStatus: 0,
+      curlStatus: 0,
+      message: 'cannot resolve endpoint host "example.invalid": getaddrinfo ENOTFOUND',
+    };
+    expect(getProbeRecovery({ failures: [failure] })).toEqual({
+      kind: "transport",
+      retry: "retry",
+      failure,
+    });
+  });
+
   it("only allows model-specific retry when explicitly enabled", () => {
     const probe = { failures: [{ httpStatus: 400, message: "unknown model" }] };
     expect(getProbeRecovery(probe)).toEqual({ kind: "unknown", retry: "selection" });

src/lib/validation-recovery.ts

@@ -32,7 +32,12 @@ export function getTransportRecoveryMessage(failure: ValidationFailureLike = {})
   if (failure.httpStatus && failure.httpStatus >= 500 && failure.httpStatus < 600) {
     return "  The provider endpoint is reachable but currently failing upstream.";
   }
-  if (failure.curlStatus === 6 || /could not resolve host|name or service not known/.test(text)) {
+  if (
+    failure.curlStatus === 6 ||
+    /cannot resolve endpoint host|did not resolve to any address|could not resolve host|name or service not known|enotfound|eai_again/.test(
+      text,
+    )
+  ) {
     return "  Validation could not resolve the provider hostname. Check DNS, VPN, or the endpoint URL.";
   }
   if (failure.curlStatus === 7 || /connection refused|failed to connect/.test(text)) {

src/lib/validation.ts

@@ -86,6 +86,13 @@ export function classifyValidationFailure({
   if (/unauthorized|forbidden|invalid api key|invalid_auth|permission/i.test(normalized)) {
     return { kind: "credential", retry: "credential" };
   }
+  if (
+    /cannot resolve endpoint host|did not resolve to any address|could not resolve host|name or service not known|enotfound|eai_again|no http response/i.test(
+      normalized,
+    )
+  ) {
+    return { kind: "transport", retry: "retry" };
+  }
   if (/ssl|tls|certificate|handshake/i.test(normalized)) {
     return { kind: "transport", retry: "retry" };
   }