diff --git a/frontends/nextjs/src/app/_components/auth-provider/auth-context.ts b/frontends/nextjs/src/app/_components/auth-provider/auth-context.ts
new file mode 100644
index 000000000..c6fbd383b
--- /dev/null
+++ b/frontends/nextjs/src/app/_components/auth-provider/auth-context.ts
@@ -0,0 +1,12 @@
+import { createContext } from 'react'
+import type { User } from '@/lib/level-types'
+
+export interface AuthContextType {
+  user: User | null
+  isLoading: boolean
+  login: (username: string, password: string) => Promise<void>
+  logout: () => Promise<void>
+  register: (username: string, email: string, password: string) => Promise<void>
+}
+
+export const AuthContext = createContext<AuthContextType | undefined>(undefined)
diff --git a/frontends/nextjs/src/app/providers.tsx b/frontends/nextjs/src/app/providers.tsx
index f5137234b..94833c34c 100644
--- a/frontends/nextjs/src/app/providers.tsx
+++ b/frontends/nextjs/src/app/providers.tsx
@@ -1,70 +1,4 @@
 'use client'
 
-import { ThemeProvider as MuiThemeProvider, CssBaseline } from '@mui/material'
-import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import { useState, useMemo, createContext, useContext } from 'react'
-import { lightTheme, darkTheme } from '@/theme/mui-theme'
-
-type ThemeMode = 'light' | 'dark' | 'system'
-
-interface ThemeContextType {
-  mode: ThemeMode
-  setMode: (mode: ThemeMode) => void
-  toggleTheme: () => void
-}
-
-const ThemeContext = createContext<ThemeContextType | undefined>(undefined)
-
-export function useTheme() {
-  const context = useContext(ThemeContext)
-  if (!context) {
-    throw new Error('useTheme must be used within Providers')
-  }
-  return context
-}
-
-export function Providers({ children }: { children: React.ReactNode }) {
-  const [queryClient] = useState(
-    () =>
-      new QueryClient({
-        defaultOptions: {
-          queries: {
-            staleTime: 60 * 1000, // 1 minute
-            retry: 1,
-          },
-        },
-      })
-  )
-
-  const [mode, setMode] = useState<ThemeMode>('system')
-  
-  const theme = useMemo(() => {
-    if (mode === 'system') {
-      // Detect system preference
-      const isDark = typeof window !== 'undefined' 
-        ? window.matchMedia('(prefers-color-scheme: dark)').matches
-        : false
-      return isDark ? darkTheme : lightTheme
-    }
-    return mode === 'dark' ? darkTheme : lightTheme
-  }, [mode])
-
-  const toggleTheme = () => {
-    setMode(current => {
-      if (current === 'light') return 'dark'
-      if (current === 'dark') return 'system'
-      return 'light'
-    })
-  }
-
-  return (
-    <ThemeContext.Provider value={{ mode, setMode, toggleTheme }}>
-      <MuiThemeProvider theme={theme}>
-        <CssBaseline />
-        <QueryClientProvider client={queryClient}>
-          {children}
-        </QueryClientProvider>
-      </MuiThemeProvider>
-    </ThemeContext.Provider>
-  )
-}
+export { Providers } from './providers/providers-component'
+export { useTheme } from './providers/use-theme'
diff --git a/frontends/nextjs/src/app/providers/providers-component.tsx b/frontends/nextjs/src/app/providers/providers-component.tsx
new file mode 100644
index 000000000..8ef029c35
--- /dev/null
+++ b/frontends/nextjs/src/app/providers/providers-component.tsx
@@ -0,0 +1,53 @@
+'use client'
+
+import { useMemo, useState } from 'react'
+import { CssBaseline, ThemeProvider as MuiThemeProvider } from '@mui/material'
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { lightTheme, darkTheme } from '@/theme/mui-theme'
+import { ThemeContext, type ThemeMode } from './theme-context'
+
+export function Providers({ children }: { children: React.ReactNode }) {
+  const [queryClient] = useState(
+    () =>
+      new QueryClient({
+        defaultOptions: {
+          queries: {
+            staleTime: 60 * 1000, // 1 minute
+            retry: 1,
+          },
+        },
+      })
+  )
+
+  const [mode, setMode] = useState<ThemeMode>('system')
+
+  const theme = useMemo(() => {
+    if (mode === 'system') {
+      // Detect system preference
+      const isDark = typeof window !== 'undefined'
+        ? window.matchMedia('(prefers-color-scheme: dark)').matches
+        : false
+      return isDark ? darkTheme : lightTheme
+    }
+    return mode === 'dark' ? darkTheme : lightTheme
+  }, [mode])
+
+  const toggleTheme = () => {
+    setMode(current => {
+      if (current === 'light') return 'dark'
+      if (current === 'dark') return 'system'
+      return 'light'
+    })
+  }
+
+  return (
+    <ThemeContext.Provider value={{ mode, setMode, toggleTheme }}>
+      <MuiThemeProvider theme={theme}>
+        <CssBaseline />
+        <QueryClientProvider client={queryClient}>
+          {children}
+        </QueryClientProvider>
+      </MuiThemeProvider>
+    </ThemeContext.Provider>
+  )
+}
diff --git a/frontends/nextjs/src/app/providers/theme-context.ts b/frontends/nextjs/src/app/providers/theme-context.ts
new file mode 100644
index 000000000..e04ff0479
--- /dev/null
+++ b/frontends/nextjs/src/app/providers/theme-context.ts
@@ -0,0 +1,11 @@
+import { createContext } from 'react'
+
+export type ThemeMode = 'light' | 'dark' | 'system'
+
+export interface ThemeContextType {
+  mode: ThemeMode
+  setMode: (mode: ThemeMode) => void
+  toggleTheme: () => void
+}
+
+export const ThemeContext = createContext<ThemeContextType | undefined>(undefined)
diff --git a/frontends/nextjs/src/app/providers/use-theme.ts b/frontends/nextjs/src/app/providers/use-theme.ts
new file mode 100644
index 000000000..4d61937d4
--- /dev/null
+++ b/frontends/nextjs/src/app/providers/use-theme.ts
@@ -0,0 +1,10 @@
+import { useContext } from 'react'
+import { ThemeContext } from './theme-context'
+
+export function useTheme() {
+  const context = useContext(ThemeContext)
+  if (!context) {
+    throw new Error('useTheme must be used within Providers')
+  }
+  return context
+}
diff --git a/frontends/nextjs/src/components/CssClassManager.tsx b/frontends/nextjs/src/components/CssClassManager.tsx
index af08561fa..4663bda39 100644
--- a/frontends/nextjs/src/components/CssClassManager.tsx
+++ b/frontends/nextjs/src/components/CssClassManager.tsx
@@ -11,6 +11,9 @@ import { Database, CssCategory } from '@/lib/database'
 import { Plus, X, Pencil, Trash, FloppyDisk } from '@phosphor-icons/react'
 import { toast } from 'sonner'
 
+const CLASS_TOKEN_PATTERN = /^[A-Za-z0-9:_/.[\]()%#!,=+-]+$/
+const uniqueClasses = (classes: string[]) => Array.from(new Set(classes))
+
 export function CssClassManager() {
   const [categories, setCategories] = useState<CssCategory[]>([])
   const [isEditing, setIsEditing] = useState(false)
@@ -18,61 +21,121 @@ export function CssClassManager() {
   const [categoryName, setCategoryName] = useState('')
   const [classes, setClasses] = useState<string[]>([])
   const [newClass, setNewClass] = useState('')
+  const [searchQuery, setSearchQuery] = useState('')
+  const [classSearchQuery, setClassSearchQuery] = useState('')
 
   useEffect(() => {
     loadCategories()
   }, [])
 
+  const normalizedSearch = searchQuery.trim().toLowerCase()
+  const filteredCategories = normalizedSearch
+    ? categories.filter((category) =>
+        category.name.toLowerCase().includes(normalizedSearch) ||
+        category.classes.some((cls) => cls.toLowerCase().includes(normalizedSearch))
+      )
+    : categories
+  const totalClassCount = categories.reduce((total, category) => total + category.classes.length, 0)
+
+  const newClassTokens = newClass.trim().split(/\s+/).filter(Boolean)
+  const uniqueNewClassTokens = Array.from(new Set(newClassTokens))
+  const invalidNewClassTokens = uniqueNewClassTokens.filter((token) => !CLASS_TOKEN_PATTERN.test(token))
+  const duplicateNewClassTokens = uniqueNewClassTokens.filter((token) => classes.includes(token))
+  const canAddClass =
+    uniqueNewClassTokens.length > 0 &&
+    invalidNewClassTokens.length === 0 &&
+    uniqueNewClassTokens.some((token) => !classes.includes(token))
+
+  const normalizedClassSearch = classSearchQuery.trim().toLowerCase()
+  const filteredEditorClasses = normalizedClassSearch
+    ? classes.filter((cls) => cls.toLowerCase().includes(normalizedClassSearch))
+    : classes
+
   const loadCategories = async () => {
     const cats = await Database.getCssClasses()
-    setCategories(cats)
+    const normalized = cats.map((category) => ({
+      ...category,
+      classes: uniqueClasses(category.classes),
+    }))
+    const sorted = normalized.slice().sort((a, b) => a.name.localeCompare(b.name))
+    setCategories(sorted)
   }
 
   const startEdit = (category?: CssCategory) => {
     if (category) {
       setEditingCategory(category)
       setCategoryName(category.name)
-      setClasses([...category.classes])
+      setClasses(uniqueClasses(category.classes))
     } else {
       setEditingCategory(null)
       setCategoryName('')
       setClasses([])
     }
+    setNewClass('')
+    setClassSearchQuery('')
     setIsEditing(true)
   }
 
   const addClass = () => {
-    if (newClass.trim()) {
-      setClasses(current => [...current, newClass.trim()])
-      setNewClass('')
+    if (uniqueNewClassTokens.length === 0) {
+      return
     }
+
+    if (invalidNewClassTokens.length > 0) {
+      toast.error(`Invalid class name: ${invalidNewClassTokens.join(', ')}`)
+      return
+    }
+
+    const newTokens = uniqueNewClassTokens.filter((token) => !classes.includes(token))
+    if (newTokens.length === 0) {
+      toast.info('Those classes already exist in this category')
+      return
+    }
+
+    setClasses((current) => uniqueClasses([...current, ...newTokens]))
+    setNewClass('')
   }
 
-  const removeClass = (index: number) => {
-    setClasses(current => current.filter((_, i) => i !== index))
+  const removeClass = (cssClass: string) => {
+    setClasses(current => current.filter((cls) => cls !== cssClass))
   }
 
   const handleSave = async () => {
-    if (!categoryName || classes.length === 0) {
+    const trimmedName = categoryName.trim()
+    const normalizedClasses = uniqueClasses(classes)
+    if (!trimmedName || normalizedClasses.length === 0) {
       toast.error('Please provide a category name and at least one class')
       return
     }
 
+    const nameConflict = categories.some((category) =>
+      category.name.toLowerCase() === trimmedName.toLowerCase() &&
+      category.name !== editingCategory?.name
+    )
+    if (nameConflict) {
+      toast.error('A category with this name already exists')
+      return
+    }
+
     const newCategory: CssCategory = {
-      name: categoryName,
-      classes,
+      name: trimmedName,
+      classes: normalizedClasses,
     }
 
-    if (editingCategory) {
-      await Database.updateCssCategory(categoryName, classes)
-      toast.success('Category updated successfully')
-    } else {
-      await Database.addCssCategory(newCategory)
-      toast.success('Category created successfully')
-    }
+    try {
+      if (editingCategory) {
+        await Database.updateCssCategory(editingCategory.name, newCategory)
+        toast.success('Category updated successfully')
+      } else {
+        await Database.addCssCategory(newCategory)
+        toast.success('Category created successfully')
+      }
 
-    setIsEditing(false)
-    loadCategories()
+      setIsEditing(false)
+      loadCategories()
+    } catch (error) {
+      toast.error('Failed to save category')
+    }
   }
 
   const handleDelete = async (categoryName: string) => {
diff --git a/frontends/nextjs/src/lib/lua/LuaEngine.ts b/frontends/nextjs/src/lib/lua/LuaEngine.ts
index 279456b85..baa1b7de6 100644
--- a/frontends/nextjs/src/lib/lua/LuaEngine.ts
+++ b/frontends/nextjs/src/lib/lua/LuaEngine.ts
@@ -13,9 +13,9 @@
 import * as fengari from 'fengari-web'
 import type { LuaExecutionContext, LuaExecutionResult } from './functions/types'
 import { setupContextAPI } from './functions/setup/setup-context-api'
-import { executeLuaCode } from './functions/execution/execute-lua-code'
+import { execute } from './functions/engine/execute'
+import { destroy } from './functions/engine/destroy'
 
-const lua = fengari.lua
 const lauxlib = fengari.lauxlib
 const lualib = fengari.lualib
 
@@ -26,8 +26,8 @@ export type { LuaExecutionContext, LuaExecutionResult }
  * LuaEngine class wraps individual Lua execution lambdas
  */
 export class LuaEngine {
-  private L: any
-  private logs: string[] = []
+  L: any
+  logs: string[] = []
 
   constructor() {
     this.L = lauxlib.luaL_newstate()
@@ -35,33 +35,11 @@ export class LuaEngine {
     setupContextAPI(this.L, this.logs)
   }
 
-  /**
-   * Execute Lua code with a context
-   * @param code - Lua code to execute
-   * @param context - Execution context
-   * @returns Execution result
-   */
-  async execute(code: string, context: LuaExecutionContext = {}): Promise<LuaExecutionResult> {
-    this.logs.length = 0
-    return executeLuaCode(this.L, code, context, this.logs)
-  }
+  /** Execute Lua code with a context */
+  execute = execute
 
-  /**
-   * Destroy the Lua state
-   */
-  destroy(): void {
-    if (this.L) {
-      lua.lua_close(this.L)
-    }
-  }
-}
-
-/**
- * Factory function to create a new LuaEngine instance
- * @returns New LuaEngine instance
- */
-export const createLuaEngine = (): LuaEngine => {
-  return new LuaEngine()
+  /** Destroy the Lua state */
+  destroy = destroy
 }
 
 // Re-export individual functions for direct imports
diff --git a/frontends/nextjs/src/lib/lua/create-lua-engine.ts b/frontends/nextjs/src/lib/lua/create-lua-engine.ts
new file mode 100644
index 000000000..439d90161
--- /dev/null
+++ b/frontends/nextjs/src/lib/lua/create-lua-engine.ts
@@ -0,0 +1,9 @@
+import { LuaEngine } from './LuaEngine'
+
+/**
+ * Factory function to create a new LuaEngine instance
+ * @returns New LuaEngine instance
+ */
+export const createLuaEngine = (): LuaEngine => {
+  return new LuaEngine()
+}
diff --git a/frontends/nextjs/src/lib/lua/functions/engine/destroy.ts b/frontends/nextjs/src/lib/lua/functions/engine/destroy.ts
new file mode 100644
index 000000000..6ffa4da4e
--- /dev/null
+++ b/frontends/nextjs/src/lib/lua/functions/engine/destroy.ts
@@ -0,0 +1,13 @@
+import * as fengari from 'fengari-web'
+import type { LuaEngine } from '../../LuaEngine'
+
+const lua = fengari.lua
+
+/**
+ * Destroy the Lua state
+ */
+export function destroy(this: LuaEngine): void {
+  if (this.L) {
+    lua.lua_close(this.L)
+  }
+}
diff --git a/frontends/nextjs/src/lib/lua/functions/engine/execute.ts b/frontends/nextjs/src/lib/lua/functions/engine/execute.ts
new file mode 100644
index 000000000..b6498c383
--- /dev/null
+++ b/frontends/nextjs/src/lib/lua/functions/engine/execute.ts
@@ -0,0 +1,18 @@
+import type { LuaExecutionContext, LuaExecutionResult } from '../types'
+import type { LuaEngine } from '../../LuaEngine'
+import { executeLuaCode } from '../execution/execute-lua-code'
+
+/**
+ * Execute Lua code with a context
+ * @param code - Lua code to execute
+ * @param context - Execution context
+ * @returns Execution result
+ */
+export async function execute(
+  this: LuaEngine,
+  code: string,
+  context: LuaExecutionContext = {}
+): Promise<LuaExecutionResult> {
+  this.logs.length = 0
+  return executeLuaCode(this.L, code, context, this.logs)
+}
diff --git a/frontends/nextjs/src/lib/lua/lua-engine.ts b/frontends/nextjs/src/lib/lua/lua-engine.ts
index 29843daf3..9325a85f6 100644
--- a/frontends/nextjs/src/lib/lua/lua-engine.ts
+++ b/frontends/nextjs/src/lib/lua/lua-engine.ts
@@ -1 +1,2 @@
 export * from './LuaEngine'
+export { createLuaEngine } from './create-lua-engine'
diff --git a/frontends/nextjs/src/lib/packages/package-glue/get-package-glue.ts b/frontends/nextjs/src/lib/packages/package-glue/get-package-glue.ts
new file mode 100644
index 000000000..266f4bf2b
--- /dev/null
+++ b/frontends/nextjs/src/lib/packages/package-glue/get-package-glue.ts
@@ -0,0 +1,3 @@
+import { packageGlue, type PackageGlue } from './package-glue'
+
+export const getPackageGlue = (): PackageGlue => packageGlue
diff --git a/frontends/nextjs/src/lib/packages/package-glue/index.ts b/frontends/nextjs/src/lib/packages/package-glue/index.ts
index 9774dfa9a..952a702b4 100644
--- a/frontends/nextjs/src/lib/packages/package-glue/index.ts
+++ b/frontends/nextjs/src/lib/packages/package-glue/index.ts
@@ -35,33 +35,5 @@ export {
   isPackageInstalled,
   uninstallPackage,
 }
-
-/**
- * PackageGlue - Wrapper class for package registry helpers
- *
- * Each method delegates to a single-function module.
- */
-export class PackageGlue {
-  buildPackageRegistry = buildPackageRegistry
-  getPackage = getPackage
-  getPackagesByCategory = getPackagesByCategory
-  getPackageComponents = getPackageComponents
-  getPackageScripts = getPackageScripts
-  getPackageScriptFiles = getPackageScriptFiles
-  getAllPackageScripts = getAllPackageScripts
-  getPackageExamples = getPackageExamples
-  checkDependencies = checkDependencies
-  installPackageComponents = installPackageComponents
-  installPackageScripts = installPackageScripts
-  installPackage = installPackage
-  uninstallPackage = uninstallPackage
-  getInstalledPackages = getInstalledPackages
-  isPackageInstalled = isPackageInstalled
-  exportAllPackagesForSeed = exportAllPackagesForSeed
-}
-
-export const packageGlue = new PackageGlue()
-
-export function getPackageGlue(): PackageGlue {
-  return packageGlue
-}
+export { PackageGlue, packageGlue } from './package-glue'
+export { getPackageGlue } from './get-package-glue'
diff --git a/frontends/nextjs/src/lib/packages/package-glue/package-glue.ts b/frontends/nextjs/src/lib/packages/package-glue/package-glue.ts
new file mode 100644
index 000000000..09e8dba29
--- /dev/null
+++ b/frontends/nextjs/src/lib/packages/package-glue/package-glue.ts
@@ -0,0 +1,42 @@
+import { buildPackageRegistry } from './build-package-registry'
+import { checkDependencies } from './check-dependencies'
+import { exportAllPackagesForSeed } from './export-all-packages-for-seed'
+import { getAllPackageScripts } from './get-all-package-scripts'
+import { getInstalledPackages } from './get-installed-packages'
+import { getPackage } from './get-package'
+import { getPackageComponents } from './get-package-components'
+import { getPackageExamples } from './get-package-examples'
+import { getPackageScriptFiles } from './get-package-script-files'
+import { getPackageScripts } from './get-package-scripts'
+import { getPackagesByCategory } from './get-packages-by-category'
+import { installPackage } from './install-package'
+import { installPackageComponents } from './install-package-components'
+import { installPackageScripts } from './install-package-scripts'
+import { isPackageInstalled } from './is-package-installed'
+import { uninstallPackage } from './uninstall-package'
+
+/**
+ * PackageGlue - Wrapper class for package registry helpers
+ *
+ * Each method delegates to a single-function module.
+ */
+export class PackageGlue {
+  buildPackageRegistry = buildPackageRegistry
+  getPackage = getPackage
+  getPackagesByCategory = getPackagesByCategory
+  getPackageComponents = getPackageComponents
+  getPackageScripts = getPackageScripts
+  getPackageScriptFiles = getPackageScriptFiles
+  getAllPackageScripts = getAllPackageScripts
+  getPackageExamples = getPackageExamples
+  checkDependencies = checkDependencies
+  installPackageComponents = installPackageComponents
+  installPackageScripts = installPackageScripts
+  installPackage = installPackage
+  uninstallPackage = uninstallPackage
+  getInstalledPackages = getInstalledPackages
+  isPackageInstalled = isPackageInstalled
+  exportAllPackagesForSeed = exportAllPackagesForSeed
+}
+
+export const packageGlue = new PackageGlue()