refactor(registry): B2 migrate to LiteLLM-style schema — unified models[] with kind field

- 71 registry files: flat `media.*Config.models` → `models[]` with `kind` field
- `media` wrapper removed → serviceKinds, *Config fields promoted top-level
- `type` field renamed to `kind` (llm/image/tts/stt/embedding/embedding/video/music)
- providers/index.js: PROVIDER_MEDIA now built from flat top-level media fields
- shared/constants/providers.js: buildProviderEntry reads flat top-level media fields
- route /v1/models: modelKind() uses kind||type; removed subConfig merge block
- models/info route: removed sub-config fallback lookup (all models in PROVIDER_MODELS)
- ttsProviders/index.js: synthesizeViaConfig reads tts models from PROVIDER_MODELS
- test-models route, helpers.js, validate route: kind||type compat
- Baselines: PROVIDERS 62/62 ✅, Alias 90/90 ✅

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

open-sse/providers/registry/vercel-ai-gateway.js

@@ -1,36 +1,39 @@
-
 export default {
-  "id": "vercel-ai-gateway",
-  "alias": "vercel-ai-gateway",
+  id: "vercel-ai-gateway",
+  alias: "vercel-ai-gateway",
+  aliases: [
+    "vercel",
+  ],
+  uiAlias: "vercel",
   display: {
-      "name": "Vercel AI Gateway",
-      "icon": "deployed_code",
-      "color": "#111827",
-      "textIcon": "VG",
-      "website": "https://vercel.com/ai-gateway",
-      "notice": {
-          "text": "Unified OpenAI-compatible endpoint from Vercel. Use your AI Gateway API key, then pick models with provider/model IDs like anthropic/claude-sonnet-4.6 or openai/gpt-5.4.",
-          "apiKeyUrl": "https://vercel.com/dashboard/~/ai-gateway"
-      }
+    name: "Vercel AI Gateway",
+    icon: "deployed_code",
+    color: "#111827",
+    textIcon: "VG",
+    website: "https://vercel.com/ai-gateway",
+    notice: {
+      text: "Unified OpenAI-compatible endpoint from Vercel. Use your AI Gateway API key, then pick models with provider/model IDs like anthropic/claude-sonnet-4.6 or openai/gpt-5.4.",
+      apiKeyUrl: "https://vercel.com/dashboard/~/ai-gateway",
+    },
   },
   category: "apikey",
-  uiAlias: "vercel",
-  passthroughModels: true,
-  aliases: ["vercel"],
-  "transport": {
-    "baseUrl": "https://ai-gateway.vercel.sh/v1/chat/completions",
-    "retry": {
-      "429": 2
+  transport: {
+    baseUrl: "https://ai-gateway.vercel.sh/v1/chat/completions",
+    retry: {
+      "429": 2,
+    },
+    usage: {
+      url: "https://ai-gateway.vercel.sh/v1/credits",
     },
-    usage: { url: "https://ai-gateway.vercel.sh/v1/credits" }
   },
-  media: {
-    serviceKinds: ["llm", "embedding", "image", "imageToText", "webSearch"],
-    searchViaChat: { defaultModel: "openai/gpt-4o-mini", pricingUrl: "https://vercel.com/docs/ai-gateway/pricing" },
-    modelsFetcher: { url: "https://ai-gateway.vercel.sh/v1/models", type: "openai" },
-    imageConfig: { baseUrl: "https://ai-gateway.vercel.sh/v1/images/generations" },
-    embeddingConfig: { baseUrl: "https://ai-gateway.vercel.sh/v1/embeddings" },
-    passthroughModels: true
+  serviceKinds: ["llm","embedding","image","imageToText","webSearch"],
+  embeddingConfig: { baseUrl: "https://ai-gateway.vercel.sh/v1/embeddings" },
+  imageConfig: { baseUrl: "https://ai-gateway.vercel.sh/v1/images/generations" },
+  searchViaChat: { defaultModel: "openai/gpt-4o-mini", pricingUrl: "https://vercel.com/docs/ai-gateway/pricing" },
+  modelsFetcher: { url: "https://ai-gateway.vercel.sh/v1/models", type: "openai" },
+  passthroughModels: true,
+  features: {
+    usage: true,
+    usageApikey: true,
   },
-  features: {"usage":true,"usageApikey":true},
 };