Update plugin binding regression tests

Cover codex custom endpoint auth aliases and replacement of previously managed codex provider args.

packages/plugins/plugin-Custom-LLM-Endpoint/tests/agent-binding.spec.ts

@@ -39,7 +39,20 @@ describe("agent binding helpers", () => {
           OPENAI_API_BASE: { type: "plain", value: "https://example.test/v1" },
           OPENAI_API_BASE_URL: { type: "plain", value: "https://example.test/v1" },
         },
-        extraArgs: ["-c", "openai_base_url=\"https://example.test/v1\""],
+        extraArgs: [
+          "-c",
+          "model_provider=\"custom\"",
+          "-c",
+          "model_providers.custom.name=\"custom\"",
+          "-c",
+          "model_providers.custom.wire_api=\"responses\"",
+          "-c",
+          "model_providers.custom.requires_openai_auth=true",
+          "-c",
+          "model_providers.custom.base_url=\"https://example.test/v1\"",
+          "-c",
+          "openai_base_url=\"https://example.test/v1\"",
+        ],
         model: "gpt-5.4",
         paperclipGlobalOpenAiProviderBinding: {
           providerId: "provider-1",
@@ -51,4 +64,64 @@ describe("agent binding helpers", () => {
       },
     });
   });
+
+  it("replaces previously managed codex provider args instead of duplicating them", () => {
+    const patch = buildOpenAiAgentPatch({
+      adapterType: "codex_local",
+      currentAdapterConfig: {
+        extraArgs: [
+          "--search",
+          "-c",
+          "model_provider=\"custom\"",
+          "-c",
+          "model_providers.custom.base_url=\"https://old.example/v1\"",
+          "-c",
+          "openai_base_url=\"https://old.example/v1\"",
+        ],
+      },
+      provider: {
+        id: "provider-2",
+        name: "New Proxy",
+        baseUrl: "https://new.example/v1",
+      },
+      apiKey: "sk-new",
+      model: "gpt-5.4",
+      syncedAt: "2026-05-01T00:00:00.000Z",
+    });
+
+    expect(patch).toEqual({
+      adapterConfig: {
+        env: {
+          CODEX_API_KEY: { type: "plain", value: "sk-new" },
+          OPENAI_API_KEY: { type: "plain", value: "sk-new" },
+          OPENAI_BASE_URL: { type: "plain", value: "https://new.example/v1" },
+          OPENAI_API_BASE: { type: "plain", value: "https://new.example/v1" },
+          OPENAI_API_BASE_URL: { type: "plain", value: "https://new.example/v1" },
+        },
+        extraArgs: [
+          "--search",
+          "-c",
+          "model_provider=\"custom\"",
+          "-c",
+          "model_providers.custom.name=\"custom\"",
+          "-c",
+          "model_providers.custom.wire_api=\"responses\"",
+          "-c",
+          "model_providers.custom.requires_openai_auth=true",
+          "-c",
+          "model_providers.custom.base_url=\"https://new.example/v1\"",
+          "-c",
+          "openai_base_url=\"https://new.example/v1\"",
+        ],
+        model: "gpt-5.4",
+        paperclipGlobalOpenAiProviderBinding: {
+          providerId: "provider-2",
+          providerName: "New Proxy",
+          providerBaseUrl: "https://new.example/v1",
+          managedByPlugin: true,
+          syncedAt: "2026-05-01T00:00:00.000Z",
+        },
+      },
+    });
+  });
 });