Initial commit: code-memory service

OpenAI-compatible FastAPI proxy with GraphRAG + persistent memory.
Includes 3-level Letta memory, CMA consolidation, AST-based code indexing.

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

.env.example

@@ -0,0 +1,5 @@
+DATABASE_URL=postgresql://codeai:codeai_secret_2026@192.168.20.17:5432/codeai_db
+OLLAMA_URL=http://192.168.20.47:11434
+EMBED_MODEL=nomic-embed-text
+CHAT_MODEL=qwen2.5-coder:7b-instruct-q4_K_M
+EMBED_DIM=768