Add routeable lesson URLs for bootcamp pages

Implement deep linking to individual lessons with URL pattern:
- Route: /bootcamp/{product-slug}/{lessonId}
- lessonId parameter is optional for backward compatibility
- When no lessonId provided, defaults to first lesson
- Clicking lessons updates URL without page reload
- URL parameter drives lesson selection on page load

Changes:
- Update App.tsx route to accept optional :lessonId parameter
- Add lessonId extraction in Bootcamp.tsx useParams
- Implement handleSelectLesson to update URL on lesson click
- Update lesson selection logic to read from URL parameter
- Fallback to first lesson if lessonId not found

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/pages/Bootcamp.tsx

@@ -55,7 +55,7 @@ interface UserReview {
 }
 
 export default function Bootcamp() {
-  const { slug } = useParams<{ slug: string }>();
+  const { slug, lessonId } = useParams<{ slug: string; lessonId?: string }>();
   const navigate = useNavigate();
   const { user, loading: authLoading } = useAuth();
 
@@ -134,7 +134,20 @@ export default function Bootcamp() {
       }));
       setModules(sortedModules);
 
-      if (sortedModules.length > 0 && sortedModules[0].lessons.length > 0) {
+      // Select lesson based on URL parameter or default to first lesson
+      const allLessons = sortedModules.flatMap(m => m.lessons);
+
+      if (lessonId) {
+        // Find the lesson by ID from URL
+        const lessonFromUrl = allLessons.find(l => l.id === lessonId);
+        if (lessonFromUrl) {
+          setSelectedLesson(lessonFromUrl);
+        } else if (allLessons.length > 0) {
+          // If lesson not found, default to first lesson
+          setSelectedLesson(allLessons[0]);
+        }
+      } else if (allLessons.length > 0 && sortedModules[0].lessons.length > 0) {
+        // No lessonId in URL, select first lesson
         setSelectedLesson(sortedModules[0].lessons[0]);
       }
     }
@@ -170,6 +183,12 @@ export default function Bootcamp() {
     return progress.some(p => p.lesson_id === lessonId);
   };
 
+  const handleSelectLesson = (lesson: Lesson) => {
+    setSelectedLesson(lesson);
+    // Update URL without full page reload
+    navigate(`/bootcamp/${slug}/${lesson.id}`);
+  };
+
   const markAsCompleted = async () => {
     if (!selectedLesson || !user || !product) return;
 
@@ -347,7 +366,7 @@ export default function Bootcamp() {
                   key={lesson.id}
                   onClick={() => {
                     if (isReleased) {
-                      setSelectedLesson(lesson);
+                      handleSelectLesson(lesson);
                       setMobileMenuOpen(false);
                     }
                   }}