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/lib/api/lnbits.ts

@@ -0,0 +1,132 @@
+interface LoginCredentials {
+  username: string
+  password: string
+}
+
+interface RegisterData {
+  username: string
+  email?: string
+  password: string
+  password_repeat: string
+}
+
+interface AuthResponse {
+  access_token: string
+  user_id: string
+  username?: string
+  email?: string
+}
+
+interface User {
+  id: string
+  username?: string
+  email?: string
+  pubkey?: string
+  created_at: string
+  updated_at: string
+}
+
+import { getApiUrl, getAuthToken, setAuthToken, removeAuthToken } from '@/lib/config/lnbits'
+
+class LnbitsAPI {
+  private accessToken: string | null = null
+
+  constructor() {
+    // Try to load token from localStorage
+    this.accessToken = getAuthToken()
+  }
+
+  private async request<T>(
+    endpoint: string,
+    options: RequestInit = {}
+  ): Promise<T> {
+    const url = getApiUrl(endpoint)
+    const headers: HeadersInit = {
+      'Content-Type': 'application/json',
+      ...options.headers,
+    }
+
+    if (this.accessToken) {
+      (headers as Record<string, string>)['Authorization'] = `Bearer ${this.accessToken}`
+    }
+
+    const response = await fetch(url, {
+      ...options,
+      headers,
+    })
+
+    if (!response.ok) {
+      const errorData = await response.json().catch(() => ({}))
+      throw new Error(errorData.detail || `HTTP ${response.status}: ${response.statusText}`)
+    }
+
+    return response.json()
+  }
+
+  async login(credentials: LoginCredentials): Promise<AuthResponse> {
+    const response = await this.request<AuthResponse>('/auth', {
+      method: 'POST',
+      body: JSON.stringify(credentials),
+    })
+
+    this.accessToken = response.access_token
+    setAuthToken(response.access_token)
+    
+    return response
+  }
+
+  async register(data: RegisterData): Promise<AuthResponse> {
+    const response = await this.request<AuthResponse>('/auth/register', {
+      method: 'POST',
+      body: JSON.stringify(data),
+    })
+
+    this.accessToken = response.access_token
+    setAuthToken(response.access_token)
+    
+    return response
+  }
+
+  async logout(): Promise<void> {
+    try {
+      await this.request('/auth/logout', {
+        method: 'POST',
+      })
+    } finally {
+      this.accessToken = null
+      removeAuthToken()
+    }
+  }
+
+  async getCurrentUser(): Promise<User> {
+    return this.request<User>('/auth')
+  }
+
+  async updatePassword(currentPassword: string, newPassword: string): Promise<User> {
+    return this.request<User>('/auth/password', {
+      method: 'PUT',
+      body: JSON.stringify({
+        current_password: currentPassword,
+        new_password: newPassword,
+      }),
+    })
+  }
+
+  async updateProfile(data: Partial<User>): Promise<User> {
+    return this.request<User>('/auth/update', {
+      method: 'PUT',
+      body: JSON.stringify(data),
+    })
+  }
+
+  isAuthenticated(): boolean {
+    return !!this.accessToken
+  }
+
+  getAccessToken(): string | null {
+    return this.accessToken
+  }
+}
+
+export const lnbitsAPI = new LnbitsAPI()
+export type { LoginCredentials, RegisterData, AuthResponse, User }