feat(invite-system): implement user invite functionality with registration mode control

src/i18n/en.json

@@ -86,7 +86,9 @@
     "emailVerificationResend": "Click here to receive a new verification email",
     "emailVerificationResendCooldown": "Resend in {seconds}s",
     "emailVerificationResendSuccess": "Verification email sent!",
-    "emailVerificationResendFailed": "Could not send verification email"
+    "emailVerificationResendFailed": "Could not send verification email",
+    "inviteOnly": "Invite Only",
+    "inviteOnlyDesc": "Registration is currently restricted. You need an invitation link from an administrator to create an account."
   },
   "home": {
     "poweredBy": "Powered by BigBlueButton",
@@ -333,7 +335,26 @@
     "defaultThemeLabel": "Default Theme",
     "defaultThemeDesc": "Applied to unauthenticated pages (guest join, login, home) when no personal preference is set.",
     "defaultThemeSaved": "Default theme saved",
-    "defaultThemeUpdateFailed": "Could not update default theme"
+    "defaultThemeUpdateFailed": "Could not update default theme",
+    "regModeTitle": "Registration Mode",
+    "regModeDescription": "Control how new users can register. \"Open\" allows everyone to sign up. \"Invite only\" requires an invitation link.",
+    "regModeOpen": "Open registration",
+    "regModeInvite": "Invite only",
+    "regModeSaved": "Registration mode updated",
+    "regModeFailed": "Could not update registration mode",
+    "inviteTitle": "User Invitations",
+    "inviteDescription": "Invite new users by email. They will receive a registration link valid for 7 days.",
+    "sendInvite": "Send invite",
+    "inviteSent": "Invitation sent!",
+    "inviteFailed": "Could not send invitation",
+    "inviteDeleted": "Invitation deleted",
+    "inviteDeleteFailed": "Could not delete invitation",
+    "inviteLinkCopied": "Invite link copied!",
+    "copyInviteLink": "Copy invite link",
+    "inviteExpired": "Expired",
+    "inviteUsedBy": "Used by",
+    "inviteExpiresAt": "Expires",
+    "noInvites": "No invitations yet"
   },
   "federation": {
     "inbox": "Invitations",