fix(coding-agent): harden clipboard copy

closes #3639

packages/ai/test/stream.test.ts

@@ -447,6 +447,33 @@ describe("Generate E2E Tests", () => {
 		});
 	});
 
+	describe.skipIf(!process.env.DEEPSEEK_API_KEY)(
+		"DeepSeek Provider (deepseek-v4-flash via OpenAI Completions)",
+		() => {
+			const llm = getModel("deepseek", "deepseek-v4-flash");
+
+			it("should complete basic text generation", { retry: 3 }, async () => {
+				await basicTextGeneration(llm);
+			});
+
+			it("should handle tool calling", { retry: 3 }, async () => {
+				await handleToolCall(llm);
+			});
+
+			it("should handle streaming", { retry: 3 }, async () => {
+				await handleStreaming(llm);
+			});
+
+			it("should handle thinking mode", { retry: 3 }, async () => {
+				await handleThinking(llm, { reasoningEffort: "high" });
+			});
+
+			it("should handle multi-turn with thinking and tools", { retry: 3 }, async () => {
+				await multiTurn(llm, { reasoningEffort: "high" });
+			});
+		},
+	);
+
 	describe.skipIf(!process.env.OPENAI_API_KEY)("OpenAI Responses Provider (gpt-5.4)", () => {
 		const llm = getModel("openai", "gpt-5.4");