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

dashboard/src/ui/widgets/mod.rs

@@ -0,0 +1,25 @@
+use cm_dashboard_shared::Metric;
+use ratatui::{layout::Rect, Frame};
+
+pub mod cpu;
+pub mod memory;
+pub mod services;
+
+pub use cpu::CpuWidget;
+pub use memory::MemoryWidget;
+pub use services::ServicesWidget;
+
+/// Widget trait for UI components that display metrics
+pub trait Widget {
+    /// Update widget with new metrics data
+    fn update_from_metrics(&mut self, metrics: &[&Metric]);
+    
+    /// Render the widget to a terminal frame
+    fn render(&mut self, frame: &mut Frame, area: Rect);
+    
+    /// Get widget name for display
+    fn get_name(&self) -> &str;
+    
+    /// Check if widget has data to display
+    fn has_data(&self) -> bool;
+}