feat(mail): sender display name (SMTP_FROM_NAME, default MindSift)

A bare SMTP_FROM address gets the display name in the From header; a name
already in SMTP_FROM wins, the envelope keeps the bare address. Also a
field in the admin mail settings.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/features/settings/AdminSettingsView.tsx

@@ -103,6 +103,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
     smtpUser: '',
     smtpPass: '',
     smtpFrom: '',
+    smtpFromName: '',
     smtpTls: true,
     smtpSkipVerify: false,
     smtpConfiguredViaEnv: false,
@@ -133,6 +134,7 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
           smtpUser: sys.smtpUser || '',
           smtpPass: sys.smtpPass || '',
           smtpFrom: sys.smtpFrom || '',
+          smtpFromName: sys.smtpFromName || '',
           smtpTls: sys.smtpTls ?? true,
           smtpSkipVerify: Boolean(sys.smtpSkipVerify),
           allowPrivateWebhooks: Boolean(sys.allowPrivateWebhooks),
@@ -1258,11 +1260,30 @@ export const AdminSettingsView: React.FC<AdminSettingsViewProps> = ({
                       onChange={(e) =>
                         setSettings((prev) => ({ ...prev, smtpFrom: e.target.value }))
                       }
-                      placeholder="MindSift <alerts@deinedomain.de>"
+                      placeholder="alerts@deinedomain.de"
                       className="w-full h-9 px-3 input-field"
                     />
                   </div>
 
+                  <div>
+                    <label className="block text-muted font-medium mb-1">
+                      Absender-Name (`SMTP_FROM_NAME`)
+                    </label>
+                    <input
+                      type="text"
+                      value={settings.smtpFromName || ''}
+                      onChange={(e) =>
+                        setSettings((prev) => ({ ...prev, smtpFromName: e.target.value }))
+                      }
+                      placeholder="MindSift"
+                      className="w-full h-9 px-3 input-field"
+                    />
+                    <p className="text-[11px] text-faint mt-1">
+                      Erscheint beim Empfänger als Absender. Leer = „MindSift“; ein Name direkt in der Adresse
+                      („Name &lt;adresse&gt;“) hat Vorrang.
+                    </p>
+                  </div>
+
                   <div className="sm:col-span-2 space-y-3 pt-1">
                     <div className="flex items-center justify-between gap-3">
                       <div>