Major refactor: Switch to complete local operation

- Remove external AI API dependency (no more OpenAI/Claude API calls)
- Claude Code now does all interpretation and scoring locally
- Zero cost: No API fees
- Complete privacy: No data sent to external servers
- Simplified dependencies: Removed openai crate and ai-analysis feature

Changes:
- ai_interpreter.rs: Simplified to lightweight wrapper
- Cargo.toml: Removed ai-analysis feature and openai dependency
- mcp/base.rs: Updated create_memory_with_ai to accept interpreted_content and priority_score from Claude Code
- memory.rs: Added create_memory_with_interpretation() method
- Documentation: Updated README, QUICKSTART, USAGE to reflect local-only operation
- Added CHANGELOG.md to track changes

How it works now:
User → Claude Code (interprets & scores) → aigpt (stores) → game result

Benefits:
✅ 完全ローカル (Fully local)
✅ ゼロコスト (Zero cost)
✅ プライバシー保護 (Privacy protected)
✅ 高速 (Faster - no network latency)
✅ シンプル (Simpler - fewer dependencies)

QUICKSTART.md

@@ -5,11 +5,8 @@
 ### ステップ1: MCPサーバーを起動
 
 ```bash
-# 基本版（AI機能なし）
+# API キー不要！完全にローカルで動作
 ./target/debug/aigpt server
-
-# AI機能有効版（OpenAI APIキーが必要）
-OPENAI_API_KEY=your_key ./target/debug/aigpt server
 ```
 
 ### ステップ2: Claude Desktop/Codeに設定