refactor: merge setup.sh into update.sh for seamless first-run

- update.sh now auto-generates .env from .env.example if missing
- Generates random JWT/SALT keys on first run
- Existing .env is never overwritten
- Deleted redundant setup.sh
- Updated all documentation references

docs/portfolio/deployment.md

@@ -17,13 +17,7 @@ NexusGuard supports three deployment modes: Docker (recommended), native install
 git clone https://git.datadunia.com/nexusguard/Nexus-Guard-Suite.git
 cd Nexus-Guard-Suite
 
-# Generate .env file
-./setup.sh
-
-# Edit configuration
-nano .env
-
-# Start all services
+# Start all services (auto-generates .env on first run)
 bash update.sh
 ```
 
@@ -49,7 +43,7 @@ DB_NAME=nexusguard
 # Redis
 REDIS_ADDR=redis:6379
 
-# Security (auto-generated by setup.sh)
+# Security (auto-generated by update.sh)
 JWT_SECRET=<hex-64-chars>
 SERVER_SALT=<hex-64-chars>