ci: fix test failures in CI by pre-populating models cache

Tests were failing in CI because the models.json cache file doesn't exist
and the data() macro fallback only works at build time, not runtime.
The preload now pre-fetches models.json and disables the background
refresh to prevent race conditions during test execution.

packages/opencode/src/provider/models.ts

@@ -4,6 +4,7 @@ import path from "path"
 import z from "zod"
 import { data } from "./models-macro" with { type: "macro" }
 import { Installation } from "../installation"
+import { Flag } from "../flag/flag"
 
 export namespace ModelsDev {
   const log = Log.create({ service: "models.dev" })
@@ -83,6 +84,7 @@ export namespace ModelsDev {
   }
 
   export async function refresh() {
+    if (Flag.OPENCODE_DISABLE_MODELS_FETCH) return
     const file = Bun.file(filepath)
     log.info("refreshing", {
       file,