fix: align codex plus-pro routing and gpt-5.3-codex defaults (#1009)

src/tests/tools/model-provider-detection.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, test } from "bun:test";
+import { isOpenAIModel } from "../../tools/manager";
+
+describe("isOpenAIModel", () => {
+  test("detects openai handles", () => {
+    expect(isOpenAIModel("openai/gpt-5.2-codex")).toBe(true);
+  });
+
+  test("detects chatgpt-plus-pro handles", () => {
+    expect(isOpenAIModel("chatgpt-plus-pro/gpt-5.3-codex")).toBe(true);
+  });
+
+  test("detects chatgpt-plus-pro model ids via models.json metadata", () => {
+    expect(isOpenAIModel("gpt-5.3-codex-plus-pro-high")).toBe(true);
+  });
+
+  test("does not detect anthropic handles", () => {
+    expect(isOpenAIModel("anthropic/claude-sonnet-4-6")).toBe(false);
+  });
+});