Fix Serilog email sink config for v4 API breaking changes

Serilog.Sinks.Email v4 renamed all configuration parameters from their
v2 names. The old names were silently ignored, so no error alert emails
were ever sent.

Parameter renames applied across all 6 appsettings.json and docker-compose:
  fromEmail → from
  toEmail   → to
  mailServer → host
  networkCredential → credentials
  enableSsl: true → connectionSecurity: StartTls
  emailSubject → subject
  outputTemplate → body
  batchPostingLimit / period removed (v4 batching uses a separate overload)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Apis/api/appsettings.json

@@ -35,19 +35,17 @@
         "Name": "Email",
         "Args": {
           "restrictedToMinimumLevel": "Error",
-          "fromEmail": "",
-          "toEmail": "",
-          "mailServer": "",
-          "networkCredential": {
+          "from": "",
+          "to": "",
+          "host": "",
+          "credentials": {
             "userName": "",
             "password": ""
           },
           "port": 587,
-          "enableSsl": true,
-          "emailSubject": "[mihes.ro API] Error Alert",
-          "outputTemplate": "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level:u3}] {SourceContext}{NewLine}{Message:lj}{NewLine}{Exception}",
-          "batchPostingLimit": 10,
-          "period": "0.00:05:00"
+          "connectionSecurity": "StartTls",
+          "subject": "[myAi API] Error Alert",
+          "body": "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level:u3}] {SourceContext}{NewLine}{Message:lj}{NewLine}{Exception}"
         }
       }
     ],