refactor: Transition to authentication system and remove identity management

- Replace identity management with a new authentication system across the application.
- Update App.vue to integrate LoginDialog and remove PasswordDialog.
- Modify Navbar.vue to handle user authentication state and logout functionality.
- Enhance Home.vue to display user information upon login.
- Implement routing changes in index.ts to enforce authentication requirements for protected routes.

src/composables/useAuth.ts

@@ -0,0 +1,166 @@
+import { ref, computed } from 'vue'
+import { lnbitsAPI, type User, type LoginCredentials, type RegisterData } from '@/lib/api/lnbits'
+
+const currentUser = ref<User | null>(null)
+const isLoading = ref(false)
+const error = ref<string | null>(null)
+
+export function useAuth() {
+  const isAuthenticated = computed(() => !!currentUser.value)
+
+  /**
+   * Initialize authentication on app start
+   */
+  async function initialize(): Promise<void> {
+    try {
+      isLoading.value = true
+      error.value = null
+
+      if (lnbitsAPI.isAuthenticated()) {
+        const user = await lnbitsAPI.getCurrentUser()
+        currentUser.value = user
+      }
+    } catch (err) {
+      error.value = err instanceof Error ? err.message : 'Failed to initialize authentication'
+      // Clear invalid token
+      await logout()
+    } finally {
+      isLoading.value = false
+    }
+  }
+
+  /**
+   * Login with username and password
+   */
+  async function login(credentials: LoginCredentials): Promise<void> {
+    try {
+      isLoading.value = true
+      error.value = null
+
+      await lnbitsAPI.login(credentials)
+      
+      // Get user details
+      const user = await lnbitsAPI.getCurrentUser()
+      currentUser.value = user
+    } catch (err) {
+      error.value = err instanceof Error ? err.message : 'Login failed'
+      throw err
+    } finally {
+      isLoading.value = false
+    }
+  }
+
+  /**
+   * Register new user
+   */
+  async function register(data: RegisterData): Promise<void> {
+    try {
+      isLoading.value = true
+      error.value = null
+
+      await lnbitsAPI.register(data)
+      
+      // Get user details
+      const user = await lnbitsAPI.getCurrentUser()
+      currentUser.value = user
+    } catch (err) {
+      error.value = err instanceof Error ? err.message : 'Registration failed'
+      throw err
+    } finally {
+      isLoading.value = false
+    }
+  }
+
+  /**
+   * Logout and clear user data
+   */
+  async function logout(): Promise<void> {
+    try {
+      await lnbitsAPI.logout()
+    } catch (err) {
+      console.error('Logout error:', err)
+    } finally {
+      currentUser.value = null
+      error.value = null
+    }
+  }
+
+  /**
+   * Update user password
+   */
+  async function updatePassword(currentPassword: string, newPassword: string): Promise<void> {
+    try {
+      isLoading.value = true
+      error.value = null
+
+      const updatedUser = await lnbitsAPI.updatePassword(currentPassword, newPassword)
+      currentUser.value = updatedUser
+    } catch (err) {
+      error.value = err instanceof Error ? err.message : 'Failed to update password'
+      throw err
+    } finally {
+      isLoading.value = false
+    }
+  }
+
+  /**
+   * Update user profile
+   */
+  async function updateProfile(data: Partial<User>): Promise<void> {
+    try {
+      isLoading.value = true
+      error.value = null
+
+      const updatedUser = await lnbitsAPI.updateProfile(data)
+      currentUser.value = updatedUser
+    } catch (err) {
+      error.value = err instanceof Error ? err.message : 'Failed to update profile'
+      throw err
+    } finally {
+      isLoading.value = false
+    }
+  }
+
+  /**
+   * Check if user is authenticated
+   */
+  function checkAuth(): boolean {
+    return lnbitsAPI.isAuthenticated()
+  }
+
+  /**
+   * Get user display info
+   */
+  const userDisplay = computed(() => {
+    if (!currentUser.value) return null
+    
+    return {
+      name: currentUser.value.username || currentUser.value.email || 'Anonymous',
+      username: currentUser.value.username,
+      email: currentUser.value.email,
+      id: currentUser.value.id,
+      shortId: currentUser.value.id.slice(0, 8) + '...' + currentUser.value.id.slice(-8)
+    }
+  })
+
+  return {
+    // State
+    currentUser: computed(() => currentUser.value),
+    isAuthenticated,
+    isLoading,
+    error,
+    userDisplay,
+
+    // Actions
+    initialize,
+    login,
+    register,
+    logout,
+    updatePassword,
+    updateProfile,
+    checkAuth
+  }
+}
+
+// Export singleton instance for global state
+export const auth = useAuth()