feat(sub): allow identity tokens on every subscription link (#5935)

Keep usage tokens first-link-only while adding an opt-in setting for repeating EMAIL and USERNAME in subscription-body remarks.

Co-authored-by: x06579 <x06579@ai-dashboard>

internal/web/translation/en-US.json

@@ -1261,6 +1261,8 @@
       "panelOutboundPh": "Direct connection",
       "remarkTemplate": "Remark Template",
       "remarkTemplateDesc": "When set, this replaces the remark model for every subscription link — write your own format with the variable tokens (use the button to insert them). Leave empty to use the model above.",
+      "subShowIdentityOnAllLinks": "Show identity on every link",
+      "subShowIdentityOnAllLinksDesc": "When enabled, {{EMAIL}} and {{USERNAME}} stay on every subscription-body remark. Usage tokens still appear on the first link only.",
       "datepicker": "Calendar Type",
       "datepickerPlaceholder": "Select date",
       "datepickerDescription": "Scheduled tasks will run based on this calendar.",