caching implementation

doc/arch.md

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+- **Frontend Service** (serving React frontend)
+  - Communicates with backend APIs via HTTPS
+  - Authenticates users via JWT tokens
+
+- **Messenger**
+  - Handles real‑time messaging (WebSocket or long polling)
+  - Stores message metadata in Postgres
+  - Uses Redis for message caching
+
+- **CDN Service** (user uploaded media)
+  - Receives uploads, stores files on object storage
+  - Generates signed URLs with built in auth for secure access
+
+- **LLM Service**
+  - Exposes language‑model inference API for scripts
+  - Runs model in a containerized environment
+  - Stores usage logs in Postgres
+
+- **Auth Service** (user authentication & authorization)
+  - Validates credentials and issues JWTs
+  - Manages refresh tokens and token revocation
+  - Persists session state and audit logs in PostgreSQL
+
+- **Script Runner**
+  - Executes user or system scripts on demand
+  - Isolates execution in sandbox containers
+  - Provides access to "Tables" - SQLite files kept in object storage
+  - Persists logs to Postgres
+
+- **Redis Cache**
+  - Provides distributed caching for session data and messages
+
+- **PostgreSQL Service** (with volumes)
+  - Stores relational data: users, messages, media metadata, script logs
+  - Uses Docker volume for persistent storage
+  - Backed up via scheduled snapshots
+```