fix: Clarify MinIO access credentials in UI

- Update CreateUserDialog labels to show 'Username (Access Key)' and 'Password (Secret Key)'
- Add helper text explaining these are MinIO credentials
- Enhanced success display to show credentials with proper MinIO terminology
- Add MinIO CLI connection examples in credential displays
- Fix confusion about where to get access key and secret key

This addresses user feedback about unclear credential terminology and aligns
with MinIO documentation where username = Access Key and password = Secret Key.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/components/Users/CreateUserDialog.tsx

@@ -126,24 +126,26 @@ const CreateUserDialog: React.FC<CreateUserDialogProps> = ({
               <TextField
                 autoFocus
                 margin="dense"
-                label="Username"
+                label="Username (Access Key)"
                 fullWidth
                 value={username}
                 onChange={(e) => setUsername(e.target.value)}
                 required
                 disabled={loading}
+                helperText="This will be the user's Access Key for MinIO"
                 sx={{ mb: 2 }}
               />
 
               <TextField
                 margin="dense"
-                label="Password"
+                label="Password (Secret Key)"
                 type={showPassword ? 'text' : 'password'}
                 fullWidth
                 value={password}
                 onChange={(e) => setPassword(e.target.value)}
                 required
                 disabled={loading}
+                helperText="This will be the user's Secret Key for MinIO"
                 InputProps={{
                   endAdornment: (
                     <InputAdornment position="end">
@@ -215,15 +217,24 @@ const CreateUserDialog: React.FC<CreateUserDialogProps> = ({
           ) : (
             <Box>
               <Alert severity="success" sx={{ mb: 2 }}>
-                User created successfully! Save these credentials securely - the password cannot be retrieved later.
+                User created successfully! Save these MinIO credentials securely - the secret key cannot be retrieved later.
               </Alert>
+              <Typography variant="h6" gutterBottom>
+                MinIO Access Credentials
+              </Typography>
               <Box sx={{ bgcolor: 'grey.100', p: 2, borderRadius: 1, mb: 2 }}>
                 <Typography variant="body2" sx={{ fontFamily: 'monospace' }}>
-                  <strong>Username:</strong> {username}
+                  <strong>Access Key:</strong> {username}
                   <br />
-                  <strong>Password:</strong> {password}
+                  <strong>Secret Key:</strong> {password}
                 </Typography>
               </Box>
+              <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
+                Use these credentials to connect via MinIO Client:
+              </Typography>
+              <Box sx={{ bgcolor: 'grey.900', color: 'grey.100', p: 1, borderRadius: 1, fontFamily: 'monospace', fontSize: '0.875rem', mb: 2 }}>
+                mc alias set myminio http://your-minio-server:9000 {username} {password}
+              </Box>
               <Tooltip title="Copy credentials to clipboard">
                 <Button
                   variant="outlined"