refactor(open-sse): registry consolidation + DRY media/oauth/adhoc cleanup

- Single-source registry: oauth clientId/tokenUrl, usage URLs, image/embed
  configs, search defaultModel, codex fixedPort, google token url derive.
- Remove 29 unused OmniRoute providers (registry 100→71); media intact.
- De-adhoc: codex literals → registry format/oauth flags; reasoningInject,
  image/embed openrouter headers + xai bodyFields config-driven.
- Add REGISTRY_TEMPLATE.js + expand PROVIDER_DEFAULTS/schema JSDoc.
- Baselines updated; PROVIDERS 62 + alias 90 byte-for-byte, golden snapshots.

Co-authored-by: Cursor <cursoragent@cursor.com>

open-sse/handlers/imageProviders/openai.js

@@ -1,40 +1,37 @@
 // OpenAI-compatible adapter (used by openai, minimax, openrouter, recraft)
+import { PROVIDER_MEDIA } from "../../providers/index.js";
 
+// media-only providers without a registry file keep their URL here; rest derive from registry media.imageConfig.baseUrl
 const ENDPOINTS = {
-  openai: "https://api.openai.com/v1/images/generations",
-  minimax: "https://api.minimaxi.com/v1/images/generations",
-  openrouter: "https://openrouter.ai/api/v1/images/generations",
   recraft: "https://external.api.recraft.ai/v1/images/generations",
-  "vercel-ai-gateway": "https://ai-gateway.vercel.sh/v1/images/generations",
-  xai: "https://api.x.ai/v1/images/generations",
 };
 
+const imageCfg = (id) => PROVIDER_MEDIA[id]?.imageConfig || {};
+const imageUrl = (id) => imageCfg(id).baseUrl || ENDPOINTS[id];
+
 export default function createOpenAIAdapter(providerId) {
+  const cfg = imageCfg(providerId);
   return {
-    buildUrl: () => ENDPOINTS[providerId],
+    buildUrl: () => imageUrl(providerId),
     buildHeaders: (creds) => {
-      const headers = { "Content-Type": "application/json" };
+      const headers = { "Content-Type": "application/json", ...(cfg.headers || {}) };
       const key = creds?.apiKey || creds?.accessToken;
       if (key) headers["Authorization"] = `Bearer ${key}`;
-      if (providerId === "openrouter") {
-        headers["HTTP-Referer"] = "https://endpoint-proxy.local";
-        headers["X-Title"] = "Endpoint Proxy";
-      }
       return headers;
     },
     buildBody: (model, body) => {
       const { prompt, n = 1, size = "1024x1024", quality, style, response_format } = body;
-      // xAI only accepts prompt, model, n, response_format
-      if (providerId === "xai") {
-        const req = { model, prompt, n };
-        if (response_format) req.response_format = response_format;
+      const full = { model, prompt, n, size };
+      if (quality) full.quality = quality;
+      if (style) full.style = style;
+      if (response_format) full.response_format = response_format;
+      // bodyFields whitelist (e.g. xAI accepts only model/prompt/n/response_format)
+      if (Array.isArray(cfg.bodyFields)) {
+        const req = {};
+        for (const f of cfg.bodyFields) if (full[f] !== undefined) req[f] = full[f];
         return req;
       }
-      const req = { model, prompt, n, size };
-      if (quality) req.quality = quality;
-      if (style) req.style = style;
-      if (response_format) req.response_format = response_format;
-      return req;
+      return full;
     },
     normalize: (responseBody) => responseBody,
   };