feat: Implement process monitoring module

- Create ProcessMonitor using sysinfo System
- Define ProcessInfo struct for process data
- Implement get_top_processes() to find high CPU processes
- Calculate CPU and memory usage percentages
- Sort processes by CPU usage (descending)
- Implement get_process_count() for total process count
- Add display_processes() for formatted console output
- Replicate Python version's process monitoring functionality

src/process.rs

@@ -0,0 +1,72 @@
+use sysinfo::System;
+
+pub struct ProcessMonitor {
+    sys: System,
+}
+
+#[derive(Debug, Clone)]
+pub struct ProcessInfo {
+    pub pid: u32,
+    pub name: String,
+    pub cpu_percent: f32,
+    pub memory_percent: f32,
+}
+
+impl ProcessMonitor {
+    pub fn new() -> Self {
+        ProcessMonitor {
+            sys: System::new_all(),
+        }
+    }
+
+    pub fn get_top_processes(&mut self, limit: usize) -> Vec<ProcessInfo> {
+        self.sys.refresh_all();
+        
+        let mut processes: Vec<ProcessInfo> = self.sys.processes()
+            .iter()
+            .map(|(pid, process)| {
+                let total_memory = self.sys.total_memory() as f32;
+                let memory_percent = if total_memory > 0.0 {
+                    (process.memory() as f32 / total_memory) * 100.0
+                } else {
+                    0.0
+                };
+
+                ProcessInfo {
+                    pid: pid.as_u32(),
+                    name: process.name().to_string_lossy().to_string(),
+                    cpu_percent: process.cpu_usage(),
+                    memory_percent,
+                }
+            })
+            .collect();
+
+        processes.sort_by(|a, b| b.cpu_percent.partial_cmp(&a.cpu_percent).unwrap());
+        processes.truncate(limit);
+        processes
+    }
+
+    pub fn get_process_count(&mut self) -> usize {
+        self.sys.refresh_all();
+        self.sys.processes().len()
+    }
+
+    pub fn display_processes(&mut self, limit: usize) {
+        println!("\nTop Processes by CPU Usage:");
+        println!("{:<10}{:<30}{:<10}{:<10}", "PID", "Name", "CPU%", "Memory%");
+        println!("{}", "-".repeat(60));
+
+        for proc in self.get_top_processes(limit) {
+            println!("{:<10}{:<30}{:<10.2}{:<10.2}", 
+                proc.pid, proc.name, proc.cpu_percent, proc.memory_percent);
+        }
+
+        println!("\nTotal Processes: {}", self.get_process_count());
+    }
+}
+
+impl Default for ProcessMonitor {
+    fn default() -> Self {
+        Self::new()
+    }
+}