chore: import upstream snapshot with attribution

tests/unit/github-copilot-gpt-4o-mini.test.ts

@@ -0,0 +1,46 @@
+import { test } from "node:test";
+import assert from "node:assert/strict";
+import { getRegistryEntry } from "../../open-sse/config/providerRegistry.ts";
+
+// Regression guard: the GitHub Copilot (`gh`) provider must expose `gpt-4o-mini`
+// alongside the curated date-pinned GPT-4o model. Copilot serves the cheaper mini variant via
+// chat/completions, so apps that hard-code `gpt-4o-mini` should resolve to the
+// Copilot provider — not only to the separate github-models (`ghm`) marketplace
+// entry, which lists it under the `openai/` prefix (`openai/gpt-4o-mini`).
+//
+// Ported from upstream decolua/9router (add GPT-4o mini to GitHub Copilot).
+
+test("github (Copilot) provider exposes gpt-4o-mini next to curated GPT-4o", () => {
+  const entry = getRegistryEntry("github");
+  assert.ok(entry, "github registry entry should exist");
+  assert.ok(entry.models, "github registry entry should have a models array");
+
+  const ids = entry.models!.map((m) => m.id);
+  assert.ok(ids.includes("gpt-4o-2024-11-20"), "date-pinned gpt-4o should remain registered");
+  assert.ok(
+    ids.includes("gpt-4o-mini"),
+    "gpt-4o-mini should be registered on the Copilot (gh) provider"
+  );
+
+  const mini = entry.models!.find((m) => m.id === "gpt-4o-mini");
+  assert.equal(mini?.name, "GPT-4o mini");
+  assert.equal(mini?.contextLength, 128000);
+  assert.equal(ids.includes("gpt-4o"), false, "bare gpt-4o is not in the curated list");
+});
+
+test("Copilot gpt-4o-mini is distinct from the github-models openai/gpt-4o-mini", () => {
+  const copilot = getRegistryEntry("github");
+  const marketplace = getRegistryEntry("github-models");
+
+  const copilotIds = (copilot?.models ?? []).map((m) => m.id);
+  const marketplaceIds = (marketplace?.models ?? []).map((m) => m.id);
+
+  // The two providers reference the same upstream model under different ids:
+  // Copilot uses the bare `gpt-4o-mini`; the marketplace uses `openai/gpt-4o-mini`.
+  assert.ok(copilotIds.includes("gpt-4o-mini"));
+  assert.ok(marketplaceIds.includes("openai/gpt-4o-mini"));
+  assert.ok(
+    !copilotIds.includes("openai/gpt-4o-mini"),
+    "Copilot should not carry the marketplace-prefixed id"
+  );
+});