feat: xAI image generate/edit, API key import, and per-provider timeouts

- Add dedicated xAI image adapter with generate + edit (multi-image) via
  /v1/images/generations and /v1/images/edits, plus aspect_ratio/resolution UI
- Support importing existing API keys and exposing connection api-key routes
- Add global/per-provider connect timeout overrides from settings
- Keep unrelated provider UX improvements on this branch; no Grok quota tracking

tests/unit/image-generation.test.js

@@ -543,4 +543,146 @@ describe("handleImageGenerationCore", () => {
     expect(result.success).toBe(true);
     expect(onRequestSuccess).toHaveBeenCalledTimes(1);
   });
+
+  it("generates image with xAI Imagine API", async () => {
+    global.fetch.mockResolvedValueOnce(
+      new Response(
+        JSON.stringify({
+          created: 1234567890,
+          data: [{ url: "https://example.com/xai-gen.png" }],
+        }),
+        { status: 200, headers: { "Content-Type": "application/json" } }
+      )
+    );
+
+    const result = await handleImageGenerationCore({
+      body: {
+        prompt: "Mountain landscape at sunrise",
+        n: 2,
+        aspect_ratio: "16:9",
+        resolution: "2k",
+        response_format: "url",
+      },
+      modelInfo: { provider: "xai", model: "grok-imagine-image-quality" },
+      credentials: { apiKey: "xai-key" },
+      log: null,
+    });
+
+    expect(result.success).toBe(true);
+    expect(global.fetch).toHaveBeenCalledWith(
+      "https://api.x.ai/v1/images/generations",
+      expect.objectContaining({
+        method: "POST",
+        headers: expect.objectContaining({
+          "Content-Type": "application/json",
+          Authorization: "Bearer xai-key",
+        }),
+      })
+    );
+
+    const reqBody = JSON.parse(global.fetch.mock.calls[0][1].body);
+    expect(reqBody).toEqual({
+      model: "grok-imagine-image-quality",
+      prompt: "Mountain landscape at sunrise",
+      n: 2,
+      response_format: "url",
+      aspect_ratio: "16:9",
+      resolution: "2k",
+    });
+  });
+
+  it("maps OpenAI size to aspect_ratio for xAI generation", async () => {
+    global.fetch.mockResolvedValueOnce(
+      new Response(
+        JSON.stringify({ created: 1, data: [{ url: "https://example.com/xai.png" }] }),
+        { status: 200, headers: { "Content-Type": "application/json" } }
+      )
+    );
+
+    await handleImageGenerationCore({
+      body: { prompt: "city", size: "1792x1024" },
+      modelInfo: { provider: "xai", model: "grok-imagine-image-quality" },
+      credentials: { accessToken: "oauth-token" },
+      log: null,
+    });
+
+    const reqBody = JSON.parse(global.fetch.mock.calls[0][1].body);
+    expect(reqBody.aspect_ratio).toBe("16:9");
+    expect(reqBody.size).toBeUndefined();
+    expect(global.fetch.mock.calls[0][1].headers.Authorization).toBe("Bearer oauth-token");
+  });
+
+  it("edits a single image via xAI /images/edits", async () => {
+    global.fetch.mockResolvedValueOnce(
+      new Response(
+        JSON.stringify({ created: 1, data: [{ url: "https://example.com/xai-edit.png" }] }),
+        { status: 200, headers: { "Content-Type": "application/json" } }
+      )
+    );
+
+    const result = await handleImageGenerationCore({
+      body: {
+        prompt: "Render this as a pencil sketch",
+        image: "https://docs.x.ai/assets/api-examples/images/style-realistic.png",
+      },
+      modelInfo: { provider: "xai", model: "grok-imagine-image-quality" },
+      credentials: { apiKey: "xai-key" },
+      log: null,
+    });
+
+    expect(result.success).toBe(true);
+    expect(global.fetch).toHaveBeenCalledWith(
+      "https://api.x.ai/v1/images/edits",
+      expect.objectContaining({ method: "POST" })
+    );
+
+    const reqBody = JSON.parse(global.fetch.mock.calls[0][1].body);
+    expect(reqBody.image).toEqual({
+      type: "image_url",
+      url: "https://docs.x.ai/assets/api-examples/images/style-realistic.png",
+    });
+    expect(reqBody.images).toBeUndefined();
+  });
+
+  it("supports multi-image edit for xAI (up to 3 refs)", async () => {
+    global.fetch.mockResolvedValueOnce(
+      new Response(
+        JSON.stringify({ created: 1, data: [{ b64_json: "abc" }] }),
+        { status: 200, headers: { "Content-Type": "application/json" } }
+      )
+    );
+
+    const result = await handleImageGenerationCore({
+      body: {
+        prompt: "Show all subjects sitting together on the grass",
+        images: [
+          "https://docs.x.ai/assets/api-examples/images/image-merge/woman.jpg",
+          { url: "https://docs.x.ai/assets/api-examples/images/image-merge/man.jpg" },
+          "rawbase64payload",
+          "https://example.com/extra-ignored.jpg",
+        ],
+        aspect_ratio: "3:2",
+        response_format: "b64_json",
+      },
+      modelInfo: { provider: "xai", model: "grok-imagine-image-quality" },
+      credentials: { apiKey: "xai-key" },
+      log: null,
+    });
+
+    expect(result.success).toBe(true);
+    expect(global.fetch).toHaveBeenCalledWith(
+      "https://api.x.ai/v1/images/edits",
+      expect.any(Object)
+    );
+
+    const reqBody = JSON.parse(global.fetch.mock.calls[0][1].body);
+    expect(reqBody.images).toEqual([
+      { type: "image_url", url: "https://docs.x.ai/assets/api-examples/images/image-merge/woman.jpg" },
+      { type: "image_url", url: "https://docs.x.ai/assets/api-examples/images/image-merge/man.jpg" },
+      { type: "image_url", url: "data:image/png;base64,rawbase64payload" },
+    ]);
+    expect(reqBody.image).toBeUndefined();
+    expect(reqBody.aspect_ratio).toBe("3:2");
+    expect(reqBody.response_format).toBe("b64_json");
+  });
 });