feat: add MiniMax provider support for PicoOraClaw

[octo-patch]

Summary

Add MiniMax as a new LLM provider for PicoOraClaw, using the OpenAI-compatible API.

Changes

• Provider integration: Add MiniMax to the provider factory (CreateProvider) with support for both explicit provider name (minimax/MiniMax) and auto-detection from model name
• Temperature handling: Clamp temperature to the valid range (0.0, 1.0] as required by the MiniMax API
• Model prefix stripping: Support minimax/model-name prefix format
• Configuration: Add minimax section to ProvidersConfig, config.example.json, and .env.example
• Documentation: Update README with provider table entry and configuration example
• Tests: Add 9 comprehensive unit tests covering chat, streaming, tool calling, temperature clamping, model prefix stripping, and provider creation

Supported Models

Model	Description
MiniMax-M2.7	Peak Performance. Ultimate Value. Master the Complex
MiniMax-M2.7-highspeed	Same performance, faster and more agile

Configuration

{
  "agents": {
    "defaults": {
      "provider": "minimax",
      "model": "MiniMax-M2.7"
    }
  },
  "providers": {
    "minimax": {
      "api_key": "your-key",
      "api_base": "https://api.minimax.io/v1"
    }
  }
}

API Reference

• Chat (OpenAI Compatible): https://platform.minimax.io/docs/api-reference/text-openai-api

Test Results

All 9 new tests pass, and all 100 existing provider tests continue to pass with no regressions.

=== RUN   TestMiniMaxProvider_ChatRoundTrip          --- PASS
=== RUN   TestMiniMaxProvider_TemperatureClamp       --- PASS (5 sub-tests)
=== RUN   TestMiniMaxProvider_ModelPrefixStripping   --- PASS
=== RUN   TestMiniMaxProvider_ToolCalling            --- PASS
=== RUN   TestMiniMaxProvider_DefaultBaseURL          --- PASS
=== RUN   TestMiniMaxProvider_Streaming              --- PASS
=== RUN   TestCreateProvider_MiniMax                 --- PASS
=== RUN   TestCreateProvider_MiniMaxDefaultBaseURL   --- PASS
=== RUN   TestCreateProvider_MiniMaxAlias            --- PASS

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• octo-patch@github.com

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[jasperan]

hey @octo-patch, could you please sign the Oracle Contributor Agreement please?