feat: switch email delivery from Resend to SMTP with libcurl integration

docs/openapi/visione.openapi.yaml

@@ -2582,7 +2582,7 @@
     },
     "/api/v1/auth/otp/request": {
       "post": {
-        "description": "Queues a one-time code by email through configured mail provider.",
+        "description": "Sends a one-time code by email through configured SMTP provider.",
         "operationId": "AuthController.requestOtp",
         "parameters": [ ],
         "requestBody": {
@@ -3312,7 +3312,7 @@
     },
     "/api/v1/reports": {
       "get": {
-        "description": "Lists reports visible to the authenticated user.",
+        "description": "Lists reports visible to the authenticated user. Citizens see own reports only; operators and admins can read all reports. Admin can use this endpoint for global read-only overview screens.",
         "operationId": "ReportController.list",
         "parameters": [
           {