chore: remove Claude Code artifacts from repository

- Delete tracked CLAUDE.md.migrated.20260308
- Update confluence-collab submodule (removed Claude Code docstring ref)
- .claude-session/ already gitignored, removed local copy

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md.migrated.20260308

@@ -1,37 +0,0 @@
-# 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.