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/translator/request/openai-to-ollama.js

@@ -1,5 +1,6 @@
 import { register } from "../index.js";
 import { FORMATS } from "../formats.js";
+import { parseDataUri } from "../helpers/imageHelper.js";
 
 /**
  * Convert OpenAI request to Ollama format
@@ -179,10 +180,10 @@ function extractImagesFromContent(content) {
     const url = typeof block.image_url === "string" ? block.image_url : block.image_url?.url;
     if (typeof url !== "string" || !url) continue;
 
-    const m = url.match(/^data:[^;]+;base64,([\s\S]+)$/);
-    if (!m) continue;
+    const parsed = parseDataUri(url);
+    if (!parsed) continue;
 
-    images.push(m[1]);
+    images.push(parsed.base64);
   }
 
   return images;