Fix CC2r: uncheck not persisting + want_license hiding cc2r when active

Issue 1 — hidden seeds overriding user input:
Removed all hidden seed inputs (cc2r, want_license, license_id,
license_custom). The .licence-license-choice div is now rendered
directly from $formData on page load instead of via HTMX load
trigger. This eliminates stale-seed interference on both HTMX
radio changes and full form submits.

Issue 2 — Interne want_license uncheck clearing CC2r:
When want_license is unchecked, CC2r and licence selections are
cleared (section hidden). Added hidden want_license=0 so the
fragment handler can distinguish "arriving from another access
type" (no want_license in POST → preserve values) from "explicit
Interne toggle" (want_license present → clear CC2r if off).

CC2r is independently toggleable within the visible section.
Licence dropdown placeholder changed to 'Aucune licence' for
an explicit no-licence choice.

app/templates/partials/form/_licence.php

@@ -35,7 +35,7 @@
 
     <?php
     $name = 'license_id'; $label = 'Licence :'; $options = $licenseTypes;
-    $selected = $licenseId; $placeholder = '— Sélectionner —'; $required = false;
+    $selected = $licenseId; $placeholder = 'Aucune licence'; $required = false;
     include APP_ROOT . '/templates/partials/form/select-field.php';
     ?>
 
@@ -54,6 +54,7 @@
 
     <div class="admin-form-group">
         <label class="admin-checkbox-label">
+            <input type="hidden" name="want_license" value="0">
             <input type="checkbox" name="want_license" value="1"
                    hx-post="<?= $hxPost ?>"
                    hx-target=".licence-license-choice"
@@ -77,7 +78,7 @@
 
     <?php
     $name = 'license_id'; $label = 'Licence :'; $options = $licenseTypes;
-    $selected = $licenseId; $placeholder = '— Sélectionner —'; $required = false;
+    $selected = $licenseId; $placeholder = 'Aucune licence'; $required = false;
     include APP_ROOT . '/templates/partials/form/select-field.php';
     ?>