refactor(open-sse): P3 provider registry — split into providers/registry/{id}.js

- 100 registry files: transport + models co-located per provider (Mongoose-style)
- providers/shared.js: shared Claude headers + OS/arch helpers (deduped)
- providers/models/helpers.js: withCodexReviewModels (kept dynamic)
- providers/index.js builds PROVIDERS + PROVIDER_MODELS = old API (content byte-for-byte)
- config/providers.js + providerModels.js → barrel re-export, keep accessors + runtime helpers
- Verified: PROVIDERS/MODELS/OAuth/alias byte-for-byte, golden translator tests pass, 0 new regression

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

open-sse/providers/registry/voyage-ai.js

@@ -0,0 +1,42 @@
+export default {
+  "id": "voyage-ai",
+  "alias": "voyage-ai",
+  "transport": null,
+  "models": [
+    {
+      "id": "voyage-3-large",
+      "name": "Voyage 3 Large",
+      "type": "embedding"
+    },
+    {
+      "id": "voyage-3.5",
+      "name": "Voyage 3.5",
+      "type": "embedding"
+    },
+    {
+      "id": "voyage-3.5-lite",
+      "name": "Voyage 3.5 Lite",
+      "type": "embedding"
+    },
+    {
+      "id": "voyage-code-3",
+      "name": "Voyage Code 3",
+      "type": "embedding"
+    },
+    {
+      "id": "voyage-finance-2",
+      "name": "Voyage Finance 2",
+      "type": "embedding"
+    },
+    {
+      "id": "voyage-law-2",
+      "name": "Voyage Law 2",
+      "type": "embedding"
+    },
+    {
+      "id": "voyage-multilingual-2",
+      "name": "Voyage Multilingual 2",
+      "type": "embedding"
+    }
+  ]
+};