Implement real-time process monitoring and fix UI hardcoded data

This commit addresses several key issues identified during development:

Major Changes:
- Replace hardcoded top CPU/RAM process display with real system data
- Add intelligent process monitoring to CpuCollector using ps command
- Fix disk metrics permission issues in systemd collector
- Optimize service collection to focus on status, memory, and disk only
- Update dashboard widgets to display live process information

Process Monitoring Implementation:
- Added collect_top_cpu_process() and collect_top_ram_process() methods
- Implemented ps-based monitoring with accurate CPU percentages
- Added filtering to prevent self-monitoring artifacts (ps commands)
- Enhanced error handling and validation for process data
- Dashboard now shows realistic values like "claude (PID 2974) 11.0%"

Service Collection Optimization:
- Removed CPU monitoring from systemd collector for efficiency
- Enhanced service directory permission error logging
- Simplified services widget to show essential metrics only
- Fixed service-to-directory mapping accuracy

UI and Dashboard Improvements:
- Reorganized dashboard layout with btop-inspired multi-panel design
- Updated system panel to include real top CPU/RAM process display
- Enhanced widget formatting and data presentation
- Removed placeholder/hardcoded data throughout the interface

Technical Details:
- Updated agent/src/collectors/cpu.rs with process monitoring
- Modified dashboard/src/ui/mod.rs for real-time process display
- Enhanced systemd collector error handling and disk metrics
- Updated CLAUDE.md documentation with implementation details

agent/src/config/loader.rs

@@ -0,0 +1,18 @@
+use anyhow::{Context, Result};
+use std::path::Path;
+use std::fs;
+use crate::config::AgentConfig;
+
+pub fn load_config<P: AsRef<Path>>(path: P) -> Result<AgentConfig> {
+    let path = path.as_ref();
+    let content = fs::read_to_string(path)
+        .with_context(|| format!("Failed to read config file: {}", path.display()))?;
+    
+    let config: AgentConfig = toml::from_str(&content)
+        .with_context(|| format!("Failed to parse config file: {}", path.display()))?;
+    
+    config.validate()
+        .with_context(|| format!("Invalid configuration in file: {}", path.display()))?;
+    
+    Ok(config)
+}