Initial commit: RAG MCP Server with relationship graph

Features:
- Vector search with Pinecone + Vertex AI embeddings
- Document relationships (link, unlink, related, graph)
- Auto-link with LLM analysis
- Intelligent merge with Gemini

Modular structure:
- clients/: Pinecone, Vertex AI
- tools/: core, relations, stats
- utils/: validation, logging

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

config.py

@@ -0,0 +1,38 @@
+"""
+Configuration module for RAG system.
+Handles environment variable loading, validation, and constants.
+"""
+import os
+from dotenv import load_dotenv
+
+# Load environment variables
+load_dotenv()
+
+# Constants
+MAX_CONTENT_LENGTH = 50000
+MAX_TAG_LENGTH = 100
+MAX_GRAPH_NODES = 100
+REQUEST_TIMEOUT = int(os.getenv("REQUEST_TIMEOUT", "30"))
+AUTO_LINK_THRESHOLD = float(os.getenv("AUTO_LINK_THRESHOLD", "0.75"))
+AUTO_LINK_TOP_K = int(os.getenv("AUTO_LINK_TOP_K", "5"))
+
+# Environment variables
+PROJECT_ID = os.getenv("GOOGLE_CLOUD_PROJECT", "hypnotic-tenure-swz46")
+LOCATION = os.getenv("GOOGLE_CLOUD_LOCATION", "us-central1")
+VERTEX_API_KEY = os.getenv("VERTEX_API_KEY")
+PINECONE_API_KEY = os.getenv("PINECONE_API_KEY")
+PINECONE_INDEX_NAME = os.getenv("PINECONE_INDEX_NAME", "memory-index")
+
+# Server settings
+FASTMCP_HOST = os.getenv("FASTMCP_HOST", "0.0.0.0")
+FASTMCP_PORT = int(os.getenv("FASTMCP_PORT", "8000"))
+
+def validate_env() -> None:
+    """Validate required environment variables are present."""
+    required = ["VERTEX_API_KEY", "PINECONE_API_KEY", "PINECONE_INDEX_NAME"]
+    missing = [k for k in required if not os.getenv(k)]
+    if missing:
+        raise RuntimeError(f"필수 환경 변수가 없습니다: {missing}")
+
+# Validate on import
+validate_env()