feat(agents) : Hugging Face Inference provider first-class support and Together API fix and Direct Injection Refactor Auths [AI-assisted] (#13472)

* initial commit

* removes assesment from docs

* resolves automated review comments

* resolves lint , type , tests , refactors , and submits

* solves : why do we have to lint the tests xD

* adds greptile fixes

* solves a type error

* solves a ci error

* refactors auths

* solves a failing test after i pulled from main lol

* solves a failing test after i pulled from main lol

* resolves token naming issue to comply with better practices when using hf / huggingface

* fixes curly lints !

* fixes failing tests for google api from main

* solve merge conflicts

* solve failing tests with a defensive check 'undefined' openrouterapi key

* fix: preserve Hugging Face auth-choice intent and token behavior (#13472) (thanks @Josephrp)

* test: resolve auth-choice cherry-pick conflict cleanup (#13472)

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/agents/huggingface-models.test.ts

@@ -0,0 +1,44 @@
+import { describe, expect, it } from "vitest";
+import {
+  discoverHuggingfaceModels,
+  HUGGINGFACE_MODEL_CATALOG,
+  buildHuggingfaceModelDefinition,
+  isHuggingfacePolicyLocked,
+} from "./huggingface-models.js";
+
+describe("huggingface-models", () => {
+  it("buildHuggingfaceModelDefinition returns config with required fields", () => {
+    const entry = HUGGINGFACE_MODEL_CATALOG[0];
+    const def = buildHuggingfaceModelDefinition(entry);
+    expect(def.id).toBe(entry.id);
+    expect(def.name).toBe(entry.name);
+    expect(def.reasoning).toBe(entry.reasoning);
+    expect(def.input).toEqual(entry.input);
+    expect(def.cost).toEqual(entry.cost);
+    expect(def.contextWindow).toBe(entry.contextWindow);
+    expect(def.maxTokens).toBe(entry.maxTokens);
+  });
+
+  it("discoverHuggingfaceModels returns static catalog when apiKey is empty", async () => {
+    const models = await discoverHuggingfaceModels("");
+    expect(models).toHaveLength(HUGGINGFACE_MODEL_CATALOG.length);
+    expect(models.map((m) => m.id)).toEqual(HUGGINGFACE_MODEL_CATALOG.map((m) => m.id));
+  });
+
+  it("discoverHuggingfaceModels returns static catalog in test env (VITEST)", async () => {
+    const models = await discoverHuggingfaceModels("hf_test_token");
+    expect(models).toHaveLength(HUGGINGFACE_MODEL_CATALOG.length);
+    expect(models[0].id).toBe("deepseek-ai/DeepSeek-R1");
+  });
+
+  describe("isHuggingfacePolicyLocked", () => {
+    it("returns true for :cheapest and :fastest refs", () => {
+      expect(isHuggingfacePolicyLocked("huggingface/deepseek-ai/DeepSeek-R1:cheapest")).toBe(true);
+      expect(isHuggingfacePolicyLocked("huggingface/deepseek-ai/DeepSeek-R1:fastest")).toBe(true);
+    });
+    it("returns false for base ref and :provider refs", () => {
+      expect(isHuggingfacePolicyLocked("huggingface/deepseek-ai/DeepSeek-R1")).toBe(false);
+      expect(isHuggingfacePolicyLocked("huggingface/foo:together")).toBe(false);
+    });
+  });
+});