feat(ai): add Kimi For Coding provider support

- Add kimi-coding provider using Anthropic Messages API
- API endpoint: https://api.kimi.com/coding/v1
- Environment variable: KIMI_API_KEY
- Models: kimi-k2-thinking (text), k2p5 (text + image)
- Add context overflow detection pattern for Kimi errors
- Add tests for all standard test suites

packages/ai/test/total-tokens.test.ts

@@ -394,6 +394,29 @@ describe("totalTokens field", () => {
 		);
 	});
 
+	// =========================================================================
+	// Kimi For Coding
+	// =========================================================================
+
+	describe.skipIf(!process.env.KIMI_API_KEY)("Kimi For Coding", () => {
+		it(
+			"kimi-k2-thinking - should return totalTokens equal to sum of components",
+			{ retry: 3, timeout: 60000 },
+			async () => {
+				const llm = getModel("kimi-coding", "kimi-k2-thinking");
+
+				console.log(`\nKimi For Coding / ${llm.id}:`);
+				const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.KIMI_API_KEY });
+
+				logUsage("First request", first);
+				logUsage("Second request", second);
+
+				assertTotalTokensEqualsComponents(first);
+				assertTotalTokensEqualsComponents(second);
+			},
+		);
+	});
+
 	// =========================================================================
 	// Vercel AI Gateway
 	// =========================================================================