fix(sub): prevent default profile page URL disclosure (#6538)

* fix(sub): prevent default profile page URL disclosure

Add explicit none, builtin, and custom profile page modes.
Preserve existing custom URLs and warn before exposing the built-in page.
Cover mode selection, legacy settings, and subscription response headers.

* fix(subscription): add profile page link options and upgrade notes

frontend/src/schemas/setting.ts

@@ -4,6 +4,9 @@ const port = z.number().int().min(1).max(65535);
 const nonNegativeInt = z.number().int().min(0);
 const absolutePath = z.string().regex(/^\//, 'pages.settings.validation.pathLeadingSlash');
 
+export const SubProfileModeSchema = z.enum(['none', 'builtin', 'custom']);
+export type SubProfileMode = z.infer<typeof SubProfileModeSchema>;
+
 export const AllSettingSchema = z
   .object({
     webListen: z.string().optional(),
@@ -50,6 +53,7 @@ export const AllSettingSchema = z
     subClashUserAgentRegex: z.string().max(2048).optional(),
     subTitle: z.string().optional(),
     subSupportUrl: z.string().optional(),
+    subProfileMode: SubProfileModeSchema.optional(),
     subProfileUrl: z.string().optional(),
     subAnnounce: z.string().optional(),
     subEnableRouting: z.boolean().optional(),