rename to "weed db"

weed/server/postgres/DESIGN.md

@@ -296,9 +296,9 @@ jdbc:postgresql://localhost:5432/default?user=seaweedfs&password=secret
 
 ```bash
 # Start PostgreSQL protocol server
-weed postgres -port=5432 -auth=trust
-weed postgres -port=5432 -auth=password -users="admin:secret,readonly:pass"
-weed postgres -port=5432 -tls-cert=server.crt -tls-key=server.key
+weed db -port=5432 -auth=trust
+weed db -port=5432 -auth=password -users="admin:secret,readonly:pass"
+weed db -port=5432 -tls-cert=server.crt -tls-key=server.key
 
 # Configuration options
 -host=localhost              # Listen host

weed/server/postgres/README.md

@@ -231,7 +231,7 @@ psql -h localhost -p 5432 -U seaweedfs -d default
 - **DESIGN.md**: Complete architecture and design overview
 - **IMPLEMENTATION.md**: Detailed implementation guide
 - **postgres-examples/**: Client examples and test scripts
-- **Command Documentation**: `weed postgres -help`
+- **Command Documentation**: `weed db -help`
 
 ## Security Considerations