feat(ai): add Hugging Face provider support

- Add huggingface to KnownProvider type
- Add HF_TOKEN env var mapping
- Process huggingface models from models.dev (14 models)
- Use openai-completions API with compat settings
- Add tests for all provider test suites
- Update documentation

fixes #994

packages/ai/test/tool-call-without-result.test.ts

@@ -168,6 +168,14 @@ describe("Tool Call Without Result Tests", () => {
 		});
 	});
 
+	describe.skipIf(!process.env.HF_TOKEN)("Hugging Face Provider", () => {
+		const model = getModel("huggingface", "moonshotai/Kimi-K2.5");
+
+		it("should filter out tool calls without corresponding tool results", { retry: 3, timeout: 30000 }, async () => {
+			await testToolCallWithoutResult(model);
+		});
+	});
+
 	describe.skipIf(!process.env.ZAI_API_KEY)("zAI Provider", () => {
 		const model = getModel("zai", "glm-4.5-flash");