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>

frontend/public/openapi.json

@@ -270,6 +270,9 @@
           "subRoutingRules": {
             "type": "string"
           },
+          "subShowIdentityOnAllLinks": {
+            "type": "boolean"
+          },
           "subSupportUrl": {
             "type": "string"
           },
@@ -441,6 +444,7 @@
           "subPort",
           "subProfileUrl",
           "subRoutingRules",
+          "subShowIdentityOnAllLinks",
           "subSupportUrl",
           "subThemeDir",
           "subTitle",
@@ -737,6 +741,9 @@
           "subRoutingRules": {
             "type": "string"
           },
+          "subShowIdentityOnAllLinks": {
+            "type": "boolean"
+          },
           "subSupportUrl": {
             "type": "string"
           },
@@ -915,6 +922,7 @@
           "subPort",
           "subProfileUrl",
           "subRoutingRules",
+          "subShowIdentityOnAllLinks",
           "subSupportUrl",
           "subThemeDir",
           "subTitle",