Remove sudo access from SERVICE_USER in guides

CI_CD_PIPELINE_SETUP_GUIDE.md

@@ -385,7 +385,6 @@ sudo apt install -y \
 
 ```bash
 sudo useradd -r -s /bin/bash -m -d /home/SERVICE_USER SERVICE_USER
-sudo usermod -aG sudo SERVICE_USER
 echo "SERVICE_USER:$(openssl rand -base64 32)" | sudo chpasswd
 ```
 
@@ -1059,7 +1058,6 @@ sudo apt install -y \
 
 ```bash
 sudo useradd -r -s /bin/bash -m -d /home/SERVICE_USER SERVICE_USER
-sudo usermod -aG sudo SERVICE_USER
 echo "SERVICE_USER:$(openssl rand -base64 32)" | sudo chpasswd
 ```
 

PRODUCTION_LINODE_MANUAL_SETUP.md

@@ -212,21 +212,20 @@ sudo apt install -y \
 
 ```bash
 sudo useradd -r -s /bin/bash -m -d /home/SERVICE_USER SERVICE_USER
-sudo usermod -aG sudo SERVICE_USER
 echo "SERVICE_USER:$(openssl rand -base64 32)" | sudo chpasswd
 ```
 
 **What this does**: 
 - Creates a dedicated service account named `SERVICE_USER`
-- Gives it sudo privileges for administrative tasks
 - Generates a random 32-character password
+- **Note**: This user has no sudo privileges for security (principle of least privilege)
 
 **Expected output**: No output (successful user creation is silent).
 
 **If something goes wrong**:
 - If user already exists: `sudo userdel -r SERVICE_USER` then retry
 - Check user creation: `id SERVICE_USER`
-- Verify sudo access: `sudo -u SERVICE_USER sudo -l`
+- Verify user exists: `getent passwd SERVICE_USER`
 
 #### 2.2 Verify Service Account