fix dead code, typo, and minor bugs in main.go, process.go and index.go (#6167)

Fixes several small issues found during code review:
- fix(xray): return explicit nil instead of stale err in getLogPath
- fix(xray): remove duplicate doc comment on GetErrorLogPath
- refactor: remove unreachable return after log.Fatalf (×4)
- fix(cli): add missing newline to listen IP success message
- fix(cli): typo "form" → "from" in migrate help text
- refactor: simplify var+assign to short declaration for server/subServer
- fix(controller): return error from getTwoFactorEnable instead of swallowing it

internal/web/controller/index.go

@@ -163,7 +163,5 @@ func (a *IndexController) csrfToken(c *gin.Context) {
 // getTwoFactorEnable retrieves the current status of two-factor authentication.
 func (a *IndexController) getTwoFactorEnable(c *gin.Context) {
 	status, err := a.settingService.GetTwoFactorEnable()
-	if err == nil {
-		jsonObj(c, status, nil)
-	}
+	jsonObj(c, status, err)
 }

internal/xray/process.go

@@ -85,7 +85,7 @@ func getLogPath(key string) (string, error) {
 			return logPath, nil
 		}
 	}
-	return "", err
+	return "", nil
 }
 
 // GetAccessLogPath reads the Xray config and returns the access log file path.
@@ -93,7 +93,6 @@ func GetAccessLogPath() (string, error) {
 	return getLogPath("access")
 }
 
-// GetErrorLogPath reads the Xray config and returns the error log file path.
 // GetErrorLogPath reads the Xray config and returns the error log file path.
 func GetErrorLogPath() (string, error) {
 	return getLogPath("error")