feat(codex): add GPT-6.1 Sol

- registry entry with responsesLite + low..max thinking levels (matches gpt-6-sol)
- pricing: $2 input / $0.10 cached / $2.50 cache write / $10 output per 1M

open-sse/providers/pricing.js

@@ -78,6 +78,7 @@ export const MODEL_PRICING = {
   // OpenAI Standard short-context pricing (developers.openai.com/api/docs/pricing).
   // Long-context pricing is higher, but this table currently stores one rate per model.
   "gpt-6-astra":                  { input: 10.00, output: 50.00, cached: 1.00,  reasoning: 50.00,  cache_creation: 12.50 },
+  "gpt-6.1-sol":                  { input: 2.00,  output: 10.00, cached: 0.10,  reasoning: 10.00,  cache_creation: 2.50  },
   "gpt-6-sol":                    { input: 2.00,  output: 10.00, cached: 0.20,  reasoning: 10.00,  cache_creation: 2.50  },
   "gpt-6-luna":                   { input: 0.10,  output: 0.50,  cached: 0.01,  reasoning: 0.50,   cache_creation: 0.125 },
   "o1":                           { input: 15.00, output: 60.00, cached: 7.50,  reasoning: 90.00,  cache_creation: 15.00 },

open-sse/providers/registry/codex.js

@@ -52,6 +52,7 @@ export default {
     },
   },
   models: [
+    { id: "gpt-6.1-sol", name: "GPT 6.1 Sol", responsesLite: true, thinkingLevels: GPT_6_LITE_THINKING_LEVELS },
     { id: "gpt-6-astra", name: "GPT 6.0 Astra" },
     { id: "gpt-6-astra[1m]", name: "GPT 6.0 Astra (extended context)", upstreamModelId: "gpt-6-astra" },
     { id: "gpt-6-sol", name: "GPT 6.0 Sol", responsesLite: true, thinkingLevels: GPT_6_LITE_THINKING_LEVELS },

tests/unit/codex-gpt6-lite.test.js

@@ -11,7 +11,7 @@ const credentials = { connectionId: "fixture", accessToken: "fixture-token" };
 afterEach(() => vi.restoreAllMocks());
 
 describe("Codex GPT-6 Sol/Luna transport", () => {
-  it.each(["gpt-6-sol", "gpt-6-luna"])("lists %s with Codex capabilities", (model) => {
+  it.each(["gpt-6.1-sol", "gpt-6-sol", "gpt-6-luna"])("lists %s with Codex capabilities", (model) => {
     const entry = getModelsByProviderId("codex").find((item) => item.id === model);
     expect(entry?.responsesLite).toBe(true);
     expect(entry?.thinkingLevels).toEqual(["low", "medium", "high", "xhigh", "max"]);
@@ -175,6 +175,14 @@ describe("Codex GPT-6 Sol/Luna transport", () => {
     expect(body.reasoning.context).toBe("all_turns");
   });
 
+  it("maps GPT-6.1 Sol's Codex-only ultra effort to max", () => {
+    const body = new CodexExecutor().transformRequest("gpt-6.1-sol", {
+      model: "gpt-6.1-sol", input: "hello", reasoning: { effort: "ultra" },
+    }, true, credentials);
+
+    expect(body.reasoning).toEqual({ effort: "max", context: "all_turns" });
+  });
+
   it("sends the Lite shape and header in the actual outbound request", async () => {
     const fetchMock = vi.spyOn(proxyFetchModule, "proxyAwareFetch").mockResolvedValue({
       ok: true, status: 200, headers: new Map(),