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/README.md

@@ -56,6 +56,7 @@ Unified LLM API with automatic model discovery, provider configuration, token an
 - **Cerebras**
 - **xAI**
 - **OpenRouter**
+- **MiniMax**
 - **GitHub Copilot** (requires OAuth, see below)
 - **Google Gemini CLI** (requires OAuth, see below)
 - **Antigravity** (requires OAuth, see below)
@@ -862,6 +863,7 @@ In Node.js environments, you can set environment variables to avoid passing API
 | xAI | `XAI_API_KEY` |
 | OpenRouter | `OPENROUTER_API_KEY` |
 | zAI | `ZAI_API_KEY` |
+| MiniMax | `MINIMAX_API_KEY` |
 | GitHub Copilot | `COPILOT_GITHUB_TOKEN` or `GH_TOKEN` or `GITHUB_TOKEN` |
 
 When set, the library automatically uses these keys: