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/grok-web.js

@@ -0,0 +1,59 @@
+export default {
+  "id": "grok-web",
+  "alias": "grok-web",
+  "transport": {
+    "baseUrl": "https://grok.com/rest/app-chat/conversations/new",
+    "format": "grok-web",
+    "authType": "cookie"
+  },
+  "models": [
+    {
+      "id": "grok-3",
+      "name": "Grok 3"
+    },
+    {
+      "id": "grok-3-mini",
+      "name": "Grok 3 Mini (Thinking)"
+    },
+    {
+      "id": "grok-3-thinking",
+      "name": "Grok 3 Thinking"
+    },
+    {
+      "id": "grok-4",
+      "name": "Grok 4"
+    },
+    {
+      "id": "grok-4-mini",
+      "name": "Grok 4 Mini (Thinking)"
+    },
+    {
+      "id": "grok-4-thinking",
+      "name": "Grok 4 Thinking"
+    },
+    {
+      "id": "grok-4-heavy",
+      "name": "Grok 4 Heavy (SuperGrok)"
+    },
+    {
+      "id": "grok-4.1-mini",
+      "name": "Grok 4.1 Mini (Thinking)"
+    },
+    {
+      "id": "grok-4.1-fast",
+      "name": "Grok 4.1 Fast"
+    },
+    {
+      "id": "grok-4.1-expert",
+      "name": "Grok 4.1 Expert"
+    },
+    {
+      "id": "grok-4.1-thinking",
+      "name": "Grok 4.1 Thinking"
+    },
+    {
+      "id": "grok-4.2",
+      "name": "Grok 4.2 (4.20 Beta)"
+    }
+  ]
+};