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/vertex.js

@@ -1,44 +1,31 @@
-
 export default {
-  "id": "vertex",
-  "alias": "vertex",
+  id: "vertex",
+  alias: "vertex",
+  aliases: [
+    "vx",
+  ],
+  uiAlias: "vx",
   display: {
-      "name": "Vertex AI",
-      "icon": "cloud",
-      "color": "#4285F4",
-      "textIcon": "VX",
-      "website": "https://cloud.google.com/vertex-ai",
-      "notice": {
-          "text": "New Google Cloud accounts get $300 free credits. Requires GCP project + Service Account with Vertex AI API enabled.",
-          "apiKeyUrl": "https://console.cloud.google.com/iam-admin/serviceaccounts"
-      }
+    name: "Vertex AI",
+    icon: "cloud",
+    color: "#4285F4",
+    textIcon: "VX",
+    website: "https://cloud.google.com/vertex-ai",
+    notice: {
+      text: "New Google Cloud accounts get $300 free credits. Requires GCP project + Service Account with Vertex AI API enabled.",
+      apiKeyUrl: "https://console.cloud.google.com/iam-admin/serviceaccounts",
+    },
   },
   category: "freeTier",
-  uiAlias: "vx",
-  aliases: ["vx"],
-  "transport": {
-    "baseUrl": "https://aiplatform.googleapis.com",
-    "format": "vertex"
+  transport: {
+    baseUrl: "https://aiplatform.googleapis.com",
+    format: "vertex",
   },
-  media: {
-    serviceKinds: ["llm", "imageToText"]
-  },
-  "models": [
-    {
-      "id": "gemini-3.1-pro-preview",
-      "name": "Gemini 3.1 Pro Preview"
-    },
-    {
-      "id": "gemini-3.1-flash-lite-preview",
-      "name": "Gemini 3.1 Flash Lite Preview"
-    },
-    {
-      "id": "gemini-3-flash-preview",
-      "name": "Gemini 3 Flash Preview"
-    },
-    {
-      "id": "gemini-2.5-flash",
-      "name": "Gemini 2.5 Flash"
-    }
-  ]
+  models: [
+    { id: "gemini-3.1-pro-preview", name: "Gemini 3.1 Pro Preview" },
+    { id: "gemini-3.1-flash-lite-preview", name: "Gemini 3.1 Flash Lite Preview" },
+    { id: "gemini-3-flash-preview", name: "Gemini 3 Flash Preview" },
+    { id: "gemini-2.5-flash", name: "Gemini 2.5 Flash" },
+  ],
+  serviceKinds: ["llm","imageToText"],
 };