refactor(todos): formulaires création et édition migrés vers Modal

frontend/src/pages/TodosPage.tsx

@@ -4,6 +4,7 @@ import type { Todo, TodoCreate, TodoFilters } from '../api/todos'
 import { fetchTodos, createTodo, updateTodo, deleteTodo, postponeTodo } from '../api/todos'
 import SwipeableRow from '../components/todos/SwipeableRow'
 import TodoForm from '../components/todos/TodoForm'
+import Modal from '../components/Modal'
 
 type EditingTodo = Todo | null
 
@@ -151,22 +152,14 @@ export default function TodosPage() {
 
       {/* Formulaire de création */}
       {showForm && (
-        <div className="glass" style={{ padding: 16, borderRadius: 10, marginBottom: 16 }}>
-          <div className="hidden lg:block">
+        <Modal title="Nouvelle tâche" onClose={() => setShowForm(false)}>
           <TodoForm onSubmit={handleCreate} onCancel={() => setShowForm(false)} extended />
-          </div>
-          <div className="block lg:hidden">
-            <TodoForm onSubmit={handleCreate} onCancel={() => setShowForm(false)} />
-          </div>
-        </div>
+        </Modal>
       )}
 
       {/* Formulaire d'édition */}
       {editingTodo && (
-        <div className="glass" style={{ padding: 16, borderRadius: 10, marginBottom: 16, borderLeft: '3px solid var(--accent)' }}>
-          <p style={{ color: 'var(--ink-3)', fontSize: 11, fontFamily: 'var(--font-ui)', marginBottom: 8, textTransform: 'uppercase', letterSpacing: 1 }}>
-            Modifier la tâche
-          </p>
+        <Modal title="Modifier la tâche" onClose={() => setEditingTodo(null)}>
           <TodoForm
             onSubmit={data => handleUpdate(editingTodo.id, data)}
             onCancel={() => setEditingTodo(null)}
@@ -182,7 +175,7 @@ export default function TodosPage() {
               tags: editingTodo.tags,
             }}
           />
-        </div>
+        </Modal>
       )}
 
       {loading && (
@@ -377,7 +370,6 @@ export default function TodosPage() {
       </div>
 
       {/* FAB mobile (au-dessus de la barre de navigation) */}
-      {!showForm && (
       <button
         className="lg:hidden"
         onClick={() => setShowForm(true)}
@@ -401,10 +393,8 @@ export default function TodosPage() {
           lineHeight: 1,
         }}
       >+</button>
-      )}
 
       {/* Bouton création laptop */}
-      {!showForm && (
       <button
         className="hidden lg:flex"
         onClick={() => setShowForm(true)}
@@ -428,7 +418,6 @@ export default function TodosPage() {
       >
         + Nouvelle tâche
       </button>
-      )}
     </div>
   )
 }