feat: Implement writing streak tracking, add chapter API routes, and introduce a BookSettings component with i18n support.

src/app/api/chapters/[id]/route.ts

@@ -36,6 +36,13 @@ export async function PUT(
         },
     });
 
+    // Update writing streak if content was explicitly updated
+    if (body.content !== undefined) {
+        import('@/lib/streak').then(({ updateWritingStreak }) => {
+            updateWritingStreak(session.user.id).catch(console.error);
+        });
+    }
+
     return NextResponse.json(updated);
 }
 

src/app/api/chapters/route.ts

@@ -34,5 +34,10 @@ export async function POST(request: NextRequest) {
         },
     });
 
+    // Update writing streak
+    import('@/lib/streak').then(({ updateWritingStreak }) => {
+        updateWritingStreak(session.user.id).catch(console.error);
+    });
+
     return NextResponse.json(chapter, { status: 201 });
 }