feat: stabilize admin dashboard, refactor group management, implement PWA, and fix routing

app/server/api/users/[id]/canvases.get.ts

@@ -7,6 +7,12 @@ export default defineEventHandler(async (event) => {
     throw createError({ statusCode: 400, message: 'User ID is required' })
   }
 
+  const user = await prisma.user.findFirst({
+    where: {
+      OR: [{ id: userId }, { username: userId }]
+    }
+  })
+
   // Get user's group memberships
   const userGroupIds = Array.from(userGroups.values())
     .filter(membership => membership.userId === userId)