Step 7: Onion service tests and documentation

[igor53627]

Parent Issue

Part of #23 (Onion service support)

Overview

Add comprehensive tests and documentation for .onion support.

Tasks

• Unit tests for each HS component
• Integration test with real .onion service
• E2E test in browser (manual or automated)
• Update README with .onion usage examples
• Document limitations and known issues
• Add .onion example to demo UI

Test Services

Consider using well-known stable .onion services:

• DuckDuckGo: duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion
• Tor Project: 2gzyxa5ihm7nsggfxnu52rck2vv4rvmdlkiu3ez2tthcrbd7d.onion

Dependencies

• Step 6: HTTP integration and .onion URL handling #42 (HTTP integration)

Acceptance Criteria

• All tests pass
• README documents .onion usage
• Demo shows working .onion fetch