feat: add self-hosted memory providers (OpenViking, Honcho, Holographic)

- Add OpenViking service (knowledge graph) using official GHCR image
- Add Honcho stack (user modeling): API + PostgreSQL pgvector + Redis
- Add Holographic config to Hermes (local SQLite, no server needed)
- Hermes: install httpx for OpenViking client
- Hermes: auto-generate config.yaml + honcho.json on first boot
- All data 100% local, zero cloud dependencies

ai/honcho/init-db.sql

@@ -0,0 +1 @@
+CREATE EXTENSION IF NOT EXISTS vector;