fix(tasks): fix task cancellation process tree leak, emit cancelled events, and refine status badges styling

internal/executor/proc_unix.go

@@ -0,0 +1,21 @@
+//go:build !windows
+
+package executor
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+func SetProcessGroupAndCancel(cmd *exec.Cmd, usePty bool) {
+	if !usePty {
+		cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	}
+	cmd.Cancel = func() error {
+		if cmd.Process != nil {
+			// Kill the entire process group by sending SIGKILL to negative PID
+			return syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
+		}
+		return nil
+	}
+}