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>

frontend/src/schemas/setting.ts

@@ -33,6 +33,11 @@ export const AllSettingSchema = z.object({
   xrayTemplateConfig: z.string().optional(),
   subEnable: z.boolean().optional(),
   subJsonEnable: z.boolean().optional(),
+  subJsonAutoDetect: z.boolean().optional(),
+  subJsonAlwaysArray: z.boolean().optional(),
+  subJsonUserAgentRegex: z.string().max(2048).optional(),
+  subClashAutoDetect: z.boolean().optional(),
+  subClashUserAgentRegex: z.string().max(2048).optional(),
   subTitle: z.string().optional(),
   subSupportUrl: z.string().optional(),
   subProfileUrl: z.string().optional(),