Initial commit: Obsidian RAG Plugin design spec and TDD

Add the original design spec (obsidian-rag-design.md) and the
comprehensive Technical Design Document covering the layered
protocol model (Transport, Session, Tool, Data), OpenClaw
interaction protocol, security layers, testing strategy, and
Windows development notes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,23 @@
+KnowledgeVault/
+KnowledgeVault/*
+
+# Obsidian RAG development data
+obsidian-rag/
+
+# Dependencies
+node_modules/
+__pycache__/
+*.pyc
+.python-version
+
+# Build output
+dist/
+*.tsbuildinfo
+
+# IDE
+.vscode/
+.idea/
+
+# OS
+.DS_Store
+Thumbs.db