chore(MAT-108): add CLAUDE.md and update .gitignore

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

.gitignore

@@ -3,3 +3,6 @@ __pycache__/
 *.pyc
 .venv/
 .claude-session/
+*.bak
+*.bak.*
+memory-db-ssl/

CLAUDE.md

@@ -0,0 +1,37 @@
+# Matrix AI Agent
+
+Matrix bot with memory, voice, RAG, and Confluence collaboration.
+
+## Deployment
+- **VM:** matrix.agiliton.internal
+- **Path:** /opt/matrix-ai-agent/
+- **Deploy:** `agiliton-deploy matrix-ai-agent`
+- **Jira project:** MAT
+
+## Architecture
+- `bot.py` — Main Matrix bot (131KB, E2EE, memory-aware)
+- `voice.py` — LiveKit voice integration
+- `agent.py` — Pipecat voice agent
+- `memory-service/` — FastAPI service for encrypted memory storage (pgvector)
+- `confluence-collab/` — Confluence collaboration MCP server
+- `article_summary/` — Article summarization + TTS
+
+## Docker Services
+- `bot` — Main bot process
+- `agent` — Voice agent (host networking)
+- `memory-service` — Memory API (port 8090, connects as `memory_app` with RLS)
+- `memory-db` — pgvector/pg17 with SSL + Row-Level Security
+
+## Memory Encryption (MAT-107)
+- Per-user Fernet encryption: `HMAC-SHA256(master_key, user_id)` key derivation
+- Encrypted fields: `fact`, `chunk_text`, `summary`
+- Embeddings unencrypted (required for vector search)
+- RLS policies enforce user isolation at DB level
+- `memory_app` role for queries, `memory` owner for DDL/health
+- SSL between memory-service and memory-db
+
+## Secrets
+All in `.env` (gitignored). Key vars:
+- `MEMORY_ENCRYPTION_KEY` — Master key for memory encryption
+- `MEMORY_APP_PASSWORD` — Restricted DB role password
+- `MATRIX_BOT_PASSWORD`, `LITELLM_API_KEY`, `ELEVENLABS_API_KEY`, etc.