refactor form structure per new spec + fix

- split jury into interne/externe/ULB,
- remove president from student form,
- add language_autre,
- split duration into pages+minutes+annexes,
- move licence to degrés d'ouverture with CC2r,
- add license_custom,
- filter PACS from student AP list,
- editable généralités help block,
- Libre toggle per settings

Fix:
- missing comma after cc4r column in schema.sql
- remove duplicate form footer from partage template
- remove couverture from student files fieldset; add promoteur ULB conditional disable via JS on Approfondi
- promoteur ULB: remove 'si applicable', make required when visible

app/public/admin/edit.php

@@ -17,6 +17,10 @@ if ($thesisId <= 0) {
 
 $autofocusField = App::consumeAutofocus();
 
+// Form help blocks for editable généralités
+$helpBlocks = Database::getInstance()->getAllFormHelpBlocks();
+$helpFn = fn(string $key) => $helpBlocks[$key]['content'] ?? '';
+
 try {
     $ctrl = ThesisEditController::create();
     $view = $ctrl->load($thesisId);