chore(vendor): import pi 0.85.1

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

third_party/pi/packages/ai/src/providers/deepseek.ts

@@ -0,0 +1,15 @@
+import { openAICompletionsApi } from "../api/openai-completions.lazy.ts";
+import { envApiKeyAuth } from "../auth/helpers.ts";
+import { createProvider, type Provider } from "../models.ts";
+import { DEEPSEEK_MODELS } from "./deepseek.models.ts";
+
+export function deepseekProvider(): Provider<"openai-completions"> {
+	return createProvider({
+		id: "deepseek",
+		name: "DeepSeek",
+		baseUrl: "https://api.deepseek.com",
+		auth: { apiKey: envApiKeyAuth("DeepSeek API key", ["DEEPSEEK_API_KEY"]) },
+		models: Object.values(DEEPSEEK_MODELS),
+		api: openAICompletionsApi(),
+	});
+}