feat: Add story points support and AI daily briefing feature

- Enhanced JIRA integration to fetch story points from multiple custom fields.
- Updated task display to show story points and their estimated duration.
- Introduced AI daily briefing banner with dynamic content loading.
- Implemented subtasks functionality with add, toggle, and delete capabilities.
- Improved task management UI with better accessibility and interaction.

api/planner.php

@@ -486,6 +486,120 @@ try {
         exit;
     }
 
+    // --- V2.0: Subtaken & Checklists ---
+
+    // 7. Subtaak toevoegen aan een taak
+    if ($action === 'add_subtask') {
+        $data = json_decode(file_get_contents('php://input'), true);
+        $taskId = (int)($data['task_id'] ?? 0);
+        $title  = trim($data['title'] ?? '');
+
+        if (!$taskId || empty($title)) {
+            echo json_encode(['error' => 'Taak-ID en titel zijn verplicht']);
+            exit;
+        }
+
+        // Controleer of de taak van deze gebruiker is
+        $stmtCheck = $db->prepare("SELECT id FROM tasks WHERE id = ? AND user_id = ?");
+        $stmtCheck->execute([$taskId, $user['id']]);
+        if (!$stmtCheck->fetchColumn()) {
+            echo json_encode(['error' => 'Taak niet gevonden']);
+            exit;
+        }
+
+        // Bereken positie (achteraan)
+        $stmtPos = $db->prepare("SELECT COALESCE(MAX(position), -1) + 1 FROM task_subtasks WHERE task_id = ?");
+        $stmtPos->execute([$taskId]);
+        $position = (int)$stmtPos->fetchColumn();
+
+        $stmt = $db->prepare("
+            INSERT INTO task_subtasks (task_id, user_id, title, is_completed, position)
+            VALUES (?, ?, ?, 0, ?)
+        ");
+        $stmt->execute([$taskId, $user['id'], substr($title, 0, 255), $position]);
+        $subtaskId = (int)$db->lastInsertId();
+
+        echo json_encode([
+            'success'  => true,
+            'subtask'  => [
+                'id'           => $subtaskId,
+                'task_id'      => $taskId,
+                'title'        => $title,
+                'is_completed' => 0,
+                'position'     => $position,
+            ]
+        ]);
+        exit;
+    }
+
+    // 8. Subtaak afvinken / openzetten
+    if ($action === 'toggle_subtask') {
+        $data = json_decode(file_get_contents('php://input'), true);
+        $subtaskId   = (int)($data['subtask_id'] ?? 0);
+        $isCompleted = !empty($data['is_completed']) ? 1 : 0;
+
+        if (!$subtaskId) {
+            echo json_encode(['error' => 'Subtaak-ID ontbreekt']);
+            exit;
+        }
+
+        $stmt = $db->prepare("
+            UPDATE task_subtasks SET is_completed = ?
+            WHERE id = ? AND user_id = ?
+        ");
+        $stmt->execute([$isCompleted, $subtaskId, $user['id']]);
+
+        echo json_encode(['success' => true, 'is_completed' => $isCompleted]);
+        exit;
+    }
+
+    // 9. Subtaak verwijderen
+    if ($action === 'delete_subtask') {
+        $data = json_decode(file_get_contents('php://input'), true);
+        $subtaskId = (int)($data['subtask_id'] ?? 0);
+
+        if (!$subtaskId) {
+            echo json_encode(['error' => 'Subtaak-ID ontbreekt']);
+            exit;
+        }
+
+        $stmt = $db->prepare("DELETE FROM task_subtasks WHERE id = ? AND user_id = ?");
+        $stmt->execute([$subtaskId, $user['id']]);
+
+        echo json_encode(['success' => true]);
+        exit;
+    }
+
+    // 10. Subtaken ophalen voor een taak
+    if ($action === 'get_subtasks') {
+        $taskId = (int)($_GET['task_id'] ?? 0);
+
+        if (!$taskId) {
+            echo json_encode(['error' => 'Taak-ID ontbreekt']);
+            exit;
+        }
+
+        // Controleer eigenaarschap
+        $stmtCheck = $db->prepare("SELECT id FROM tasks WHERE id = ? AND user_id = ?");
+        $stmtCheck->execute([$taskId, $user['id']]);
+        if (!$stmtCheck->fetchColumn()) {
+            echo json_encode(['error' => 'Taak niet gevonden']);
+            exit;
+        }
+
+        $stmt = $db->prepare("
+            SELECT id, task_id, title, is_completed, position
+            FROM task_subtasks
+            WHERE task_id = ? AND user_id = ?
+            ORDER BY position ASC, created_at ASC
+        ");
+        $stmt->execute([$taskId, $user['id']]);
+        $subtasks = $stmt->fetchAll();
+
+        echo json_encode(['success' => true, 'subtasks' => $subtasks]);
+        exit;
+    }
+
     echo json_encode(['error' => 'Onbekende actie']);
 } catch (Exception $e) {
     http_response_code(500);