Todo: daily reminders at fixed time, no date, simplified sidebar

- Remove date field; due_time is now required
- Cron repeats daily via notified_date (resets at midnight)
- Remove Today/Upcoming/Overdue smart views from sidebar
- Task card shows bell icon + time instead of date labels
- Creation no longer sends immediate Discord notification (cron only)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

todo.php

@@ -74,22 +74,17 @@ require __DIR__ . '/header.php';
 
       <div class="form-row">
         <div class="form-group">
-          <label class="form-label">Date limite</label>
-          <input type="date" id="todo-form-due" class="form-control">
+          <label class="form-label">Heure de rappel *</label>
+          <input type="time" id="todo-form-time" class="form-control" required>
         </div>
         <div class="form-group">
-          <label class="form-label">Heure</label>
-          <input type="time" id="todo-form-time" class="form-control">
+          <label class="form-label">Liste</label>
+          <select id="todo-form-list" class="form-control">
+            <option value="">— Aucune —</option>
+          </select>
         </div>
       </div>
 
-      <div class="form-group">
-        <label class="form-label">Liste</label>
-        <select id="todo-form-list" class="form-control">
-          <option value="">— Aucune —</option>
-        </select>
-      </div>
-
       <div class="form-group">
         <label class="form-label">Priorité</label>
         <div class="priority-opts">