feat(sub): auto-detect subscription format by User-Agent (Updated) (#5826)

* feat(settings): add subscription format controls

* feat(sub): auto-detect subscription formats

* fix(xray): validate balancer regexes before save

* Revert "fix(xray): validate balancer regexes before save"

This reverts commit 8a208ce71b.

* doc(endpoints): align indent spaces

* doc(settings): improve error message formatting in validateSubUserAgentRegex

- Use NewErrorf with proper formatting instead of NewError with string concatenation
- Add comment explaining the rationale for returning original pattern value
- This preserves the intentional design where empty input is stored as empty
  in the DB and inherited as the runtime default at read time

---------

Co-authored-by: Tomilla <5007859+Tomilla@users.noreply.github.com>
Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

internal/web/entity/entity.go

@@ -65,6 +65,11 @@ type AllSetting struct {
 
 	SubEnable                   bool   `json:"subEnable" form:"subEnable"`
 	SubJsonEnable               bool   `json:"subJsonEnable" form:"subJsonEnable"`
+	SubJsonAutoDetect           bool   `json:"subJsonAutoDetect" form:"subJsonAutoDetect"`
+	SubJsonAlwaysArray          bool   `json:"subJsonAlwaysArray" form:"subJsonAlwaysArray"`
+	SubJsonUserAgentRegex       string `json:"subJsonUserAgentRegex" form:"subJsonUserAgentRegex"`
+	SubClashAutoDetect          bool   `json:"subClashAutoDetect" form:"subClashAutoDetect"`
+	SubClashUserAgentRegex      string `json:"subClashUserAgentRegex" form:"subClashUserAgentRegex"`
 	SubTitle                    string `json:"subTitle" form:"subTitle"`
 	SubSupportUrl               string `json:"subSupportUrl" form:"subSupportUrl"`
 	SubProfileUrl               string `json:"subProfileUrl" form:"subProfileUrl"`