feat(app): add studentOnly pages and new routes

Add routes for modules, users, notes import, recap, and islands edit.
Update middleware to filter pages based on user role.

feat(admin): add modal for assigning teaching, replace delete icon with SVG

refactor(server): rename port variable to uppercase and add env support
feat(admin): add enseignants, users, filtering and role colors

refactor(AdminRoles): improve role UI and add permission mapping

feat(admin-users): add role colors, role filter, and modal for creating users

feat(admin): add EditModule component for module editing

feat(admin): add EditUser page for editing users and managing enseignements

feat(promo-select): display id and name in options for promo dropdown

feat: add edit module/user routes, inline coeff editing, UI tweaks

refactor: UI – icons, modal overlay, grid, subtitles, import margin

static/styles/ui.css

@@ -470,6 +470,18 @@
    Permission toggle cards (role management)
 ------------------------------------------------------- */
 
+.perm-header-bar {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  padding: 0.6rem 0.85rem;
+  margin-bottom: 1.25rem;
+  background: light-dark(#f5f4ff, #141228);
+  border: 1px solid
+    light-dark(var(--light-foreground-dimmer), var(--dark-foreground-dimmer));
+  border-radius: 4px;
+}
+
 .perm-toggle-grid {
   display: grid;
   grid-template-columns: 1fr 1fr;
@@ -740,7 +752,7 @@
 .form-grid {
   display: grid;
   grid-template-columns: repeat(auto-fill, minmax(10rem, 1fr));
-  gap: 0.5rem;
+  gap: 0.75rem 1rem;
   margin-bottom: 0.75rem;
 }
 
@@ -947,6 +959,49 @@
    (end note recap)
 ------------------------------------------------------- */
 
+/* -------------------------------------------------------
+   Modal overlay
+------------------------------------------------------- */
+
+.modal-overlay {
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.5);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  z-index: 100;
+}
+
+.modal-box {
+  background: light-dark(white, #1a172d);
+  border: 1px solid
+    light-dark(var(--light-foreground-dimmer), var(--dark-foreground-dimmer));
+  border-radius: 6px;
+  padding: 1.25rem;
+  min-width: 22rem;
+  max-width: 90vw;
+}
+
+.modal-title {
+  font-size: 0.95rem;
+  font-weight: var(--font-weight-bold);
+  margin: 0 0 1rem;
+}
+
+.modal-form {
+  display: flex;
+  flex-direction: column;
+  gap: 0.6rem;
+  margin-bottom: 1rem;
+}
+
+.modal-actions {
+  display: flex;
+  justify-content: flex-end;
+  gap: 0.5rem;
+}
+
 .info-note-dim {
   font-size: 0.7rem;
   color: light-dark(var(--light-foreground-dim), var(--dark-foreground-dim));