Update from Git Manager GUI

src/backup/BackupProvider.js

@@ -0,0 +1,59 @@
+/**
+ * BackupProvider — Abstract base class for backup providers
+ * All providers must implement these methods
+ */
+
+class BackupProvider {
+  /**
+   * Authenticate with the backup service
+   * @param {Object} credentials - Provider-specific credentials
+   */
+  async authenticate(credentials) {
+    throw new Error('authenticate() not implemented in ' + this.constructor.name)
+  }
+
+  /**
+   * Upload a backup file
+   * @param {Buffer} buffer - File content
+   * @param {string} filename - Filename (e.g., 'repo-backup-2025-03-24.zip')
+   * @returns {Promise<{size: number}>}
+   */
+  async uploadBackup(buffer, filename) {
+    throw new Error('uploadBackup() not implemented in ' + this.constructor.name)
+  }
+
+  /**
+   * List all backups for a repository
+   * @returns {Promise<Array>} Array of {name, size, date}
+   */
+  async listBackups() {
+    throw new Error('listBackups() not implemented in ' + this.constructor.name)
+  }
+
+  /**
+   * Download a specific backup
+   * @param {string} filename - Filename to download
+   * @returns {Promise<Buffer>}
+   */
+  async downloadBackup(filename) {
+    throw new Error('downloadBackup() not implemented in ' + this.constructor.name)
+  }
+
+  /**
+   * Delete a backup file
+   * @param {string} filename - Filename to delete
+   */
+  async deleteBackup(filename) {
+    throw new Error('deleteBackup() not implemented in ' + this.constructor.name)
+  }
+
+  /**
+   * Test connection to backup service
+   * @returns {Promise<{ok: boolean, error?: string}>}
+   */
+  async testConnection() {
+    throw new Error('testConnection() not implemented in ' + this.constructor.name)
+  }
+}
+
+module.exports = BackupProvider