Fix service control by adding .service suffix to systemctl commands

Service stop/start operations were failing because systemctl commands
were missing the .service suffix. This caused the new user-stopped
tracking feature to mark services but not actually control them.

Changes:
- Add .service suffix to systemctl commands in service control handler
- Matches pattern used throughout systemd collector
- Fixes service start/stop functionality via dashboard

Clean up legacy documentation:
- Remove outdated TODO.md, AGENTS.md, and test files
- Update CLAUDE.md with current architecture and rules only
- Comprehensive README.md rewrite with technical documentation
- Document user-stopped service tracking feature

Bump version to v0.1.44

agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-agent"
-version = "0.1.43"
+version = "0.1.44"
 edition = "2021"
 
 [dependencies]

agent/src/agent.rs

@@ -314,7 +314,7 @@ impl Agent {
         let output = tokio::process::Command::new("sudo")
             .arg("systemctl")
             .arg(action_str)
-            .arg(service_name)
+            .arg(format!("{}.service", service_name))
             .output()
             .await?;