design: panel-words - two choices of the panel kept

Following c5edbd8, two lines where the panel had already decided on
purpose, with tests that hold it (server_test.go,
TestUserDeleteSaysNothingOfReportAddresses; the user form's e-mail help):
deleting a user names no domain - "The domains" read as if one could lose
something - and the e-mail field of the user form is "the user's own
address", not "for notifications". The mockups take the panel's words.

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

docs/assets/panel-redesign/panel/user.html

@@ -82,7 +82,7 @@
             <div class="sp-box-body">
               <div class="field"><label class="label" for="username">Username</label><div class="control"><input class="input" id="username" name="username" value="acme-ops" autocomplete="username" spellcheck="false" required></div></div>
               <div class="field"><label class="label" for="email">E-mail</label><div class="control"><input class="input" id="email" name="email" type="email" value="ops@acme.io" autocomplete="off"></div>
-                <p class="help">For notifications. The user can change it under Account.</p></div>
+                <p class="help">The user's own address. They can change it under Account.</p></div>
               <div class="field"><label class="label" for="password">Password</label><div class="control"><input class="input" id="password" name="password" type="password" autocomplete="new-password"></div>
                 <p class="help">Leave empty to keep the current one.</p></div>
               <div class="field"><label class="label" for="role">Role</label>