feat(registratie): WP-34 — phone field + BRP address read-only

Reshape the adreswijziging form into a contact-change form: the BRP address is
authoritative and shown read-only (you change it at the gemeente), and the phone
number becomes the editable/submittable field. New Telefoonnummer value object
(parse-don't-validate); backend RejectPhoneChange re-validates as authority.
POST /change-requests now carries { telefoon } (typed client regenerated).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/locale/messages.en.xlf

@@ -1074,12 +1074,12 @@
           <context context-type="linenumber">93</context>
         </context-group>
       </trans-unit>
-      <trans-unit id="validation.straat" datatype="html">
-        <source>Vul straat en huisnummer in.</source>
-        <target datatype="html">Enter a street and house number.</target>
+      <trans-unit id="validation.telefoon" datatype="html">
+        <source>Voer een geldig telefoonnummer in, bijv. 0612345678.</source>
+        <target datatype="html">Enter a valid phone number, e.g. 0612345678.</target>
         <context-group purpose="location">
-          <context context-type="sourcefile">src/app/registratie/domain/change-request.machine.ts</context>
-          <context context-type="linenumber">43</context>
+          <context context-type="sourcefile">src/app/registratie/domain/value-objects/telefoonnummer.ts</context>
+          <context context-type="linenumber">18</context>
         </context-group>
       </trans-unit>
       <trans-unit id="validation.straat2" datatype="html">
@@ -1295,8 +1295,8 @@
         </context-group>
       </trans-unit>
       <trans-unit id="changeRequest.success" datatype="html">
-        <source> Uw adreswijziging is ontvangen (referentie <x id="INTERPOLATION" equiv-text="{{ referentie() }}"/>). U ontvangt binnen 5 werkdagen bericht. </source>
-        <target datatype="html"> Your address change has been received (reference <x id="INTERPOLATION" equiv-text="{{ referentie() }}"/>). You will hear from us within 5 business days. </target>
+        <source> Uw wijziging is ontvangen (referentie <x id="INTERPOLATION" equiv-text="{{ referentie() }}"/>). U ontvangt binnen 5 werkdagen bericht. </source>
+        <target datatype="html"> Your change has been received (reference <x id="INTERPOLATION" equiv-text="{{ referentie() }}"/>). You will hear from us within 5 business days. </target>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/registratie/ui/change-request-form/change-request-form.component.ts</context>
           <context context-type="linenumber">28,30</context>
@@ -1311,13 +1311,45 @@
         </context-group>
       </trans-unit>
       <trans-unit id="changeRequest.heading" datatype="html">
-        <source>Adreswijziging doorgeven</source>
-        <target datatype="html">Report address change</target>
+        <source>Contactgegevens wijzigen</source>
+        <target datatype="html">Change contact details</target>
         <context-group purpose="location">
           <context context-type="sourcefile">src/app/registratie/ui/change-request-form/change-request-form.component.ts</context>
           <context context-type="linenumber">40,41</context>
         </context-group>
       </trans-unit>
+      <trans-unit id="changeRequest.brpAdresLabel" datatype="html">
+        <source>Adres (BRP)</source>
+        <target datatype="html">Address (BRP)</target>
+        <context-group purpose="location">
+          <context context-type="sourcefile">src/app/registratie/ui/change-request-form/change-request-form.component.ts</context>
+          <context context-type="linenumber">42</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="changeRequest.brpAdresBron" datatype="html">
+        <source> Uw adres komt uit de Basisregistratie Personen en kan hier niet worden gewijzigd. Wijzig het bij uw gemeente. </source>
+        <target datatype="html"> Your address comes from the Personal Records Database (BRP) and cannot be changed here. Change it at your municipality. </target>
+        <context-group purpose="location">
+          <context context-type="sourcefile">src/app/registratie/ui/change-request-form/change-request-form.component.ts</context>
+          <context context-type="linenumber">43</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="changeRequest.telefoonLabel" datatype="html">
+        <source>Telefoonnummer</source>
+        <target datatype="html">Phone number</target>
+        <context-group purpose="location">
+          <context context-type="sourcefile">src/app/registratie/ui/change-request-form/change-request-form.component.ts</context>
+          <context context-type="linenumber">50</context>
+        </context-group>
+      </trans-unit>
+      <trans-unit id="changeRequest.telefoonPlaceholder" datatype="html">
+        <source>0612345678</source>
+        <target datatype="html">0612345678</target>
+        <context-group purpose="location">
+          <context context-type="sourcefile">src/app/registratie/ui/change-request-form/change-request-form.component.ts</context>
+          <context context-type="linenumber">50</context>
+        </context-group>
+      </trans-unit>
       <trans-unit id="changeRequest.failed" datatype="html">
         <source>Het indienen is niet gelukt:</source>
         <target datatype="html">Submission failed:</target>