Update Simple terminal to match GNOME Terminal color scheme

Changed Simple terminal output to use the same GNOME Terminal colors as
Interactive mode for consistency.

Changes:
- Background: #2E3436 (was #300A24 purple)
- Foreground: #D3D7CF (was #F8F8F2)
- Border and scrollbar colors updated to match GNOME theme
- Text colors: bright blue (#729FCF) and green (#8AE234)

Both Simple and Interactive terminals now have matching appearance.

https://claude.ai/code/session_011PzvkCnVrsatoxbY3HbGXz

frontend/components/TerminalModal/TerminalOutput.tsx

@@ -9,28 +9,28 @@ export default function TerminalOutput({ output, containerName, outputRef }: Ter
       ref={outputRef}
       elevation={0}
       sx={{
-        backgroundColor: '#300A24',
-        color: '#F8F8F2',
-        fontFamily: '"Ubuntu Mono", "Courier New", monospace',
+        backgroundColor: '#2E3436',
+        color: '#D3D7CF',
+        fontFamily: '"Ubuntu Mono", "DejaVu Sans Mono", "Courier New", monospace',
         fontSize: { xs: '12px', sm: '14px' },
         padding: { xs: 1.5, sm: 2 },
         minHeight: { xs: '300px', sm: '400px' },
         maxHeight: { xs: '400px', sm: '500px' },
         overflowY: 'auto',
         mb: 2,
-        border: '1px solid #5E2750',
+        border: '1px solid #1C1F20',
         borderRadius: '4px',
         '&::-webkit-scrollbar': {
           width: { xs: '6px', sm: '10px' },
         },
         '&::-webkit-scrollbar-track': {
-          background: '#2C0922',
+          background: '#1C1F20',
         },
         '&::-webkit-scrollbar-thumb': {
-          background: '#5E2750',
+          background: '#555753',
           borderRadius: '5px',
           '&:hover': {
-            background: '#772953',
+            background: '#729FCF',
           }
         },
       }}
@@ -38,15 +38,15 @@ export default function TerminalOutput({ output, containerName, outputRef }: Ter
       {output.length === 0 ? (
         <Box>
           <Typography sx={{
-            color: '#8BE9FD',
+            color: '#729FCF',
             fontFamily: 'inherit',
             fontSize: '13px',
             mb: 1
           }}>
-            Ubuntu-style Terminal - Connected to <span style={{ color: '#50FA7B', fontWeight: 'bold' }}>{containerName}</span>
+            Ubuntu-style Terminal - Connected to <span style={{ color: '#8AE234', fontWeight: 'bold' }}>{containerName}</span>
           </Typography>
           <Typography sx={{
-            color: '#6272A4',
+            color: '#555753',
             fontFamily: 'inherit',
             fontSize: '12px'
           }}>