chore(frontend): split fixture and generated model snapshots

frontend/src/data/latest_models.json

@@ -1,24 +0,0 @@
-{
-  "generated_at": "2026-05-09T21:30:54+08:00",
-  "total": 2,
-  "free": 1,
-  "paid": 1,
-  "models": [
-    {
-      "id": "openai/gpt-4o",
-      "context_length": 128000,
-      "pricing": {
-        "input": 2.5,
-        "output": 10
-      }
-    },
-    {
-      "id": "anthropic/claude-3.5-sonnet:free",
-      "context_length": 200000,
-      "pricing": {
-        "input": 0,
-        "output": 0
-      }
-    }
-  ]
-}

frontend/src/lib/models.ts

@@ -111,6 +111,8 @@ export function normalizeModel(raw: any): Model | null {
 }
 
 export async function loadFallbackModels() {
+  // latest_models.json is a local runtime snapshot when present.
+  // models.json is the committed fixture fallback kept in the repo.
   const sources = [
     () => import('../data/latest_models.json'),
     () => import('../data/models.json'),