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)

Cargo.toml

@@ -38,11 +38,8 @@ dirs = "5.0"
 # Extended features (optional)
 reqwest = { version = "0.11", features = ["json"], optional = true }
 scraper = { version = "0.18", optional = true }
-openai = { version = "1.1", optional = true }
 
 [features]
 default = []
-extended = ["semantic-search", "ai-analysis", "web-integration"]
-semantic-search = ["openai"]
-ai-analysis = ["openai"] 
+extended = ["web-integration"]
 web-integration = ["reqwest", "scraper"]