feat: Add configuration export functionality with flexible options

[tvarohohlavy]

feat: Add configuration export functionality with flexible options

Summary

Adds the ability to export ZeroByte configuration as JSON files for backup, migration, or Infrastructure as Code (IaC) workflows.

Features

• Export dialogs for full configuration export
• Flexible export options:
  • Include/exclude database IDs, timestamps, runtime state (status, last backup info, health checks)
  • Secrets handling: exclude, keep encrypted, or export as cleartext
  • Recovery key export
  • Password hash export for user migration

Changes

• New ExportDialog UI component
• API endpoint at /api/v1/config/export with query parameter support
• Export buttons added to:
  • Settings page (full config)
• Updated README with export documentation

Notes

• Runtime state fields are excluded by default to produce cleaner IaC-friendly exports
• Encrypted fields are auto-detected using cryptoUtils.isEncrypted()
• ~~Volume secrets are not encrypted in DB at the moment, needs to be done in separate PR~~
• Future enhancement: password-protected ZIP export (deferred)
• Future enhancement: config backup automation (deferred)
• Future enhancement: config import via UI (deferred)
• Config import via json submitted as separate PR: https://github.com/nicotsx/zerobyte/pull/93

Related Issues

• https://github.com/nicotsx/zerobyte/issues/13

Summary by CodeRabbit

• New Features

  • Export Configuration: new Settings dialog to download your full configuration as JSON, with options for metadata, secrets handling (exclude/encrypted/cleartext), include recovery key and password-hash — password verification required.
  • Reorder Backup Schedules: ability to reorder backup schedules for customized organization.

• Documentation

  • Added user-facing instructions for the export workflow to the README.

_{✏️ Tip: You can customize this high-level summary in your review settings.}