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/providers/registry/deepgram.js

@@ -1,9 +1,29 @@
+
 export default {
   "id": "deepgram",
   "alias": "deepgram",
+  display: {
+      "name": "Deepgram",
+      "icon": "mic",
+      "color": "#13EF93",
+      "textIcon": "DG",
+      "website": "https://deepgram.com",
+      "notice": {
+          "text": "$200 free credit on signup (no card required). Aura-1: $0.015/1k chars, Aura-2: $0.030/1k chars (Pay-As-You-Go).",
+          "apiKeyUrl": "https://console.deepgram.com/api-keys"
+      }
+  },
+  category: "apikey",
+  uiAlias: "dg",
+  authType: "apikey",
+  aliases: ["dg"],
   "transport": {
     "baseUrl": "https://api.deepgram.com/v1/listen"
   },
+  media: {
+    serviceKinds: ["stt"],
+    sttConfig: { baseUrl: "https://api.deepgram.com/v1/listen", authType: "apikey", authHeader: "token", format: "deepgram", models: [{ id: "nova-3", name: "Nova 3" }, { id: "nova-2", name: "Nova 2" }, { id: "nova", name: "Nova" }] }
+  },
   "models": [
     {
       "id": "nova-3",