docs: update remaining docs for 12 LLM platforms

Update platform counts (4→12) in:
- docs/reference/CLAUDE_INTEGRATION.md (EN + zh-CN)
- docs/guides/MCP_SETUP.md, UPLOAD_GUIDE.md, MIGRATION_GUIDE.md
- docs/strategy/INTEGRATION_STRATEGY.md, DEEPWIKI_ANALYSIS.md, KIMI_ANALYSIS_COMPARISON.md
- docs/archive/historical/HTTPX_SKILL_GRADING.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/reference/CLAUDE_INTEGRATION.md

@@ -22,7 +22,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 ### Recent Updates (December 2025):
 
 **🎉 MAJOR RELEASE: Multi-Platform Feature Parity! (v2.5.0)**
-- **🌐 Multi-LLM Support**: Full support for 4 platforms - Claude AI, Google Gemini, OpenAI ChatGPT, Generic Markdown
+- **🌐 Multi-LLM Support**: Full support for 12 platforms - Claude AI, Google Gemini, OpenAI ChatGPT, MiniMax AI, OpenCode, Kimi, DeepSeek, Qwen, OpenRouter, Together AI, Fireworks AI, Generic Markdown
 - **🔄 Complete Feature Parity**: All skill modes work with all platforms
 - **🏗️ Platform Adaptors**: Clean architecture with platform-specific implementations
 - **✨ 26 MCP Tools**: Enhanced with multi-platform support (package, upload, enhance)