⚡ Bolt: Optimize video list generation in HomeView

.jules/bolt.md

@@ -44,3 +44,7 @@
 ## 2026-08-28 - Dart Collection For Loops over .map().toList()
 **Learning:** In Dart, chaining `.map().toList()` when parsing collections like Firestore query snapshots creates an intermediate `MappedIterable` and closure object, which increases heap allocation and garbage collection pressure.
 **Action:** Use a collection `for` loop (e.g., `[for (final doc in snapshot.docs) Model.fromFirestore(doc)]`) to directly construct the list and avoid unnecessary object allocation.
+
+## 2026-09-02 - Flutter Iterable Chaining Performance
+**Learning:** In Flutter, chaining iterable methods like `.take(n)` or `.indexed` within widget `build` methods allocates intermediate iterable objects on every rebuild, unnecessarily increasing garbage collection pressure.
+**Action:** Replace chained iterable methods in widget `build` methods with explicit collection `for` loops or standard aggregation loops to prevent unnecessary object allocation.

lib/services/course_service.dart

@@ -2,7 +2,10 @@ import 'package:cloud_firestore/cloud_firestore.dart';
 import '../models/course.dart';
 
 class CourseService {
-  final FirebaseFirestore _db = FirebaseFirestore.instance;
+  final FirebaseFirestore _db;
+
+  CourseService({FirebaseFirestore? db})
+      : _db = db ?? FirebaseFirestore.instance;
 
   // Optimization: Added optional limit parameter to prevent unbounded reads
   Future<List<Course>> getRecommendedCourses({int? limit}) async {

lib/views/home/home_view.dart

@@ -447,11 +447,13 @@ class _HomeViewState extends State<HomeView> {
 
   Widget _buildVideoList() {
     return Column(
-      // ⚡ Bolt: Optimize mapping with .indexed for better list generation performance
+      // ⚡ Bolt: Replaced .take(5).indexed with an explicit for loop to avoid intermediate iterable allocations during rebuilds.
       children: [
-        for (final (index, video) in _videos.take(5).indexed)
+        for (var index = 0;
+            index < (_videos.length < 5 ? _videos.length : 5);
+            index++)
           _buildVideoCard(
-            video,
+            _videos[index],
             AppTheme.cardGradients[index % AppTheme.cardGradients.length],
           ),
       ],

pubspec.lock

@@ -452,10 +452,10 @@ packages:
     dependency: transitive
     description:
       name: matcher
-      sha256: dc0b7dc7651697ea4ff3e69ef44b0407ea32c487a39fff6a4004fa585e901861
+      sha256: "12956d0ad8390bbcc63ca2e1469c0619946ccb52809807067a7020d57e647aa6"
       url: "https://pub.dev"
     source: hosted
-    version: "0.12.19"
+    version: "0.12.18"
   material_color_utilities:
     dependency: transitive
     description:
@@ -713,10 +713,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: "8161c84903fd860b26bfdefb7963b3f0b68fee7adea0f59ef805ecca346f0c7a"
+      sha256: "93167629bfc610f71560ab9312acdda4959de4df6fac7492c89ff0d3886f6636"
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.10"
+    version: "0.7.9"
   typed_data:
     dependency: transitive
     description: