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

open-sse/handlers/imageProviders/xai.js

@@ -0,0 +1,137 @@
+// xAI Grok Imagine — text-to-image + single/multi image editing
+// Docs:
+//   https://docs.x.ai/developers/model-capabilities/images/generation
+//   https://docs.x.ai/developers/model-capabilities/images/editing
+//   https://docs.x.ai/developers/model-capabilities/images/multi-image-editing
+import { sizeToAspectRatio } from "./_base.js";
+import { PROVIDER_MEDIA } from "../../providers/index.js";
+
+const IMG_CFG = PROVIDER_MEDIA["xai"]?.imageConfig || {};
+const GENERATIONS_URL = IMG_CFG.baseUrl || "https://api.x.ai/v1/images/generations";
+const EDITS_URL = IMG_CFG.editsUrl || "https://api.x.ai/v1/images/edits";
+
+const ASPECT_RATIOS = new Set([
+  "auto",
+  "1:1",
+  "16:9",
+  "9:16",
+  "4:3",
+  "3:2",
+  "2:3",
+  "9:19.5",
+  "20:9",
+]);
+
+function hasEditInput(body) {
+  if (!body || typeof body !== "object") return false;
+  if (body.image) return true;
+  return Array.isArray(body.images) && body.images.some(Boolean);
+}
+
+/** Normalize client image input → xAI image ref object */
+function toXaiImageRef(input) {
+  if (!input) return null;
+
+  if (typeof input === "object") {
+    // Already xAI-shaped or partial
+    if (input.file_id) {
+      return {
+        type: input.type || "image_url",
+        file_id: input.file_id,
+        ...(input.url ? { url: input.url } : {}),
+      };
+    }
+    if (input.url) {
+      return { type: input.type || "image_url", url: input.url };
+    }
+    return null;
+  }
+
+  if (typeof input !== "string") return null;
+  const trimmed = input.trim();
+  if (!trimmed) return null;
+
+  // Public URL or data URI
+  if (/^https?:\/\//i.test(trimmed) || /^data:image\//i.test(trimmed)) {
+    return { type: "image_url", url: trimmed };
+  }
+
+  // Raw base64 → data URI
+  return { type: "image_url", url: `data:image/png;base64,${trimmed}` };
+}
+
+function collectImageRefs(body) {
+  const refs = [];
+  if (Array.isArray(body.images)) {
+    for (const item of body.images) {
+      const ref = toXaiImageRef(item);
+      if (ref) refs.push(ref);
+    }
+  }
+  if (body.image) {
+    const ref = toXaiImageRef(body.image);
+    if (ref) refs.push(ref);
+  }
+  // xAI multi-edit supports up to 3 source images
+  return refs.slice(0, 3);
+}
+
+function resolveAspectRatio(body) {
+  if (typeof body.aspect_ratio === "string" && body.aspect_ratio.trim()) {
+    const ratio = body.aspect_ratio.trim();
+    if (ASPECT_RATIOS.has(ratio)) return ratio;
+    // Pass through unknown ratio strings (upstream will validate)
+    return ratio;
+  }
+  // OpenAI-style size → aspect ratio (skip auto)
+  if (body.size && body.size !== "auto") {
+    return sizeToAspectRatio(body.size);
+  }
+  return undefined;
+}
+
+function resolveResolution(body) {
+  if (typeof body.resolution !== "string") return undefined;
+  const value = body.resolution.trim().toLowerCase();
+  if (!value || value === "auto") return undefined;
+  return value; // "1k" | "2k"
+}
+
+export default {
+  buildUrl: (_model, _credentials, body) => (hasEditInput(body) ? EDITS_URL : GENERATIONS_URL),
+
+  buildHeaders: (creds) => {
+    const headers = { "Content-Type": "application/json", ...(IMG_CFG.headers || {}) };
+    const key = creds?.apiKey || creds?.accessToken;
+    if (key) headers["Authorization"] = `Bearer ${key}`;
+    return headers;
+  },
+
+  buildBody: (model, body) => {
+    const req = {
+      model,
+      prompt: body.prompt,
+    };
+
+    if (body.n != null) req.n = body.n;
+    if (body.response_format) req.response_format = body.response_format;
+
+    const aspectRatio = resolveAspectRatio(body);
+    if (aspectRatio) req.aspect_ratio = aspectRatio;
+
+    const resolution = resolveResolution(body);
+    if (resolution) req.resolution = resolution;
+
+    const refs = collectImageRefs(body);
+    if (refs.length === 1) {
+      req.image = refs[0];
+    } else if (refs.length > 1) {
+      req.images = refs;
+    }
+
+    return req;
+  },
+
+  // xAI already returns OpenAI-compatible { created, data: [{ url | b64_json }] }
+  normalize: (responseBody) => responseBody,
+};