feat: Integrate Electric SQL for real-time notifications and enhance PostgreSQL configuration

- Added Electric SQL service to docker-compose for real-time data synchronization.
- Introduced PostgreSQL configuration for logical replication and performance tuning.
- Created scripts for initializing Electric SQL user and electrifying tables.
- Implemented notification model and service in the backend.
- Developed ElectricProvider and useNotifications hook in the frontend for managing notifications.
- Updated environment variables and package dependencies for Electric SQL integration.

scripts/docker/postgresql.conf

@@ -0,0 +1,20 @@
+# PostgreSQL configuration for Electric SQL
+# This file is mounted into the PostgreSQL container
+
+listen_addresses = '*'
+max_connections = 200
+shared_buffers = 256MB
+
+# Enable logical replication (required for Electric SQL)
+wal_level = logical
+max_replication_slots = 10
+max_wal_senders = 10
+
+# Performance settings
+checkpoint_timeout = 10min
+max_wal_size = 1GB
+min_wal_size = 80MB
+
+# Logging (optional, for debugging)
+# log_statement = 'all'
+# log_replication_commands = on