Refactor terminal.py to enhance plugin management and system compatibility

- Moved various functions related to plugin validation and quarantine to the zdtt.plugins module for better organization and reusability.
- Updated the handling of protected commands to source from the plugins module.
- Refactored status bar management functions to utilize the zdtt.status_bar module, improving code clarity and separation of concerns.
- Simplified the display banner and compatibility warning functions by delegating to the zdtt.ui module.
- Enhanced the command execution process by integrating shell command execution from the zdtt.shell module.

zdtt/shell.py

@@ -0,0 +1,82 @@
+"""
+System shell command execution utilities for ZDTT.
+"""
+import sys
+import subprocess
+import time as time_module
+
+
+def execute_system_command(terminal, command: str):
+    """Execute a system command with real-time I/O streaming."""
+    status_bar_was_running = terminal.status_bar_thread and terminal.status_bar_thread.is_alive()
+    try:
+        process = subprocess.Popen(
+            command,
+            shell=True,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            stdin=sys.stdin,
+            bufsize=1,
+            text=True,
+            cwd=terminal.current_dir
+        )
+
+        early_output = []
+        start_time = time_module.time()
+        check_timeout = 0.1
+        hide_output = False
+        output_buffer = []
+
+        try:
+            while True:
+                char = process.stdout.read(1)
+                if not char:
+                    if process.poll() is not None:
+                        break
+                    time_module.sleep(0.01)
+                    continue
+
+                if time_module.time() - start_time < check_timeout:
+                    early_output.append(char)
+                    combined = ''.join(early_output).lower()
+                    if 'command not found' in combined or 'not found:' in combined:
+                        hide_output = True
+                        while process.poll() is None:
+                            process.stdout.read(1)
+                        break
+
+                output_buffer.append(char)
+                if char == '\n' or len(output_buffer) >= 1024:
+                    if not hide_output:
+                        sys.stdout.write(''.join(output_buffer))
+                        sys.stdout.flush()
+                    output_buffer.clear()
+
+            if output_buffer and not hide_output:
+                sys.stdout.write(''.join(output_buffer))
+                sys.stdout.flush()
+
+            process.wait()
+        except BrokenPipeError:
+            pass
+    except KeyboardInterrupt:
+        try:
+            if 'process' in locals():
+                process.terminate()
+                process.wait(timeout=1)
+        except Exception:
+            try:
+                if 'process' in locals():
+                    process.kill()
+            except Exception:
+                pass
+        print("\n^C")
+    except Exception as e:
+        if not locals().get('hide_output', False):
+            print(f"{terminal.COLOR_ERROR}Error executing command: {e}{terminal.COLOR_RESET}")
+    finally:
+        if status_bar_was_running:
+            terminal._render_status_bar()
+
+
+