Add MiniMax provider support (#656 by @dannote)

- Add minimax to KnownProvider and Api types
- Add MINIMAX_API_KEY to getEnvApiKey()
- Generate MiniMax-M2 and MiniMax-M2.1 models
- Add context overflow detection pattern
- Add tests to all required test files
- Update README and CHANGELOG with attribution

Also fixes:
- Bedrock duplicate toolResult ID when content has multiple blocks
- Sandbox extension unused parameter lint warning

packages/ai/test/unicode-surrogate.test.ts

@@ -618,6 +618,22 @@ describe("AI Providers Unicode Surrogate Pair Tests", () => {
 		});
 	});
 
+	describe.skipIf(!process.env.MINIMAX_API_KEY)("MiniMax Provider Unicode Handling", () => {
+		const llm = getModel("minimax", "MiniMax-M2.1");
+
+		it("should handle emoji in tool results", { retry: 3, timeout: 30000 }, async () => {
+			await testEmojiInToolResults(llm);
+		});
+
+		it("should handle real-world LinkedIn comment data with emoji", { retry: 3, timeout: 30000 }, async () => {
+			await testRealWorldLinkedInData(llm);
+		});
+
+		it("should handle unpaired high surrogate (0xD83D) in tool results", { retry: 3, timeout: 30000 }, async () => {
+			await testUnpairedHighSurrogate(llm);
+		});
+	});
+
 	describe.skipIf(!hasBedrockCredentials())("Amazon Bedrock Provider Unicode Handling", () => {
 		const llm = getModel("amazon-bedrock", "global.anthropic.claude-sonnet-4-5-20250929-v1:0");