feat: Add SOCKS5 Proxy Support with Bootstrap Only Mode

[scrense-hash]

Summary

This PR adds SOCKS5 proxy support to Session Desktop with a "Bootstrap Only" mode, allowing users to route traffic through a SOCKS5 proxy server to bypass network restrictions and Deep Packet Inspection (DPI).

Key Features

1. Full SOCKS5 Proxy Support

• Route all application traffic through a SOCKS5 proxy server
• Support for authenticated (username/password) and unauthenticated proxies
• TLS options preservation through proxy (certificate pinning still works)
• Automatic retry and timeout handling for proxy connections

2. Bootstrap Only Mode

• NEW: Optional mode to use proxy only for initial connection phase
• When enabled, proxy is used only for SEED_NODE connections (node discovery)
• All other traffic (SERVICE_NODE, SOGS, etc.) sent directly
• Useful for bypassing initial connection blocks while maintaining direct P2P performance

3. Proxy Settings UI

• New "Proxy" page in Settings
• Toggle to enable/disable proxy
• Bootstrap Only mode toggle
• Configure host, port, username (optional), password (optional)
• Input validation and error handling
• Settings saved and applied immediately

Technical Implementation

Core Changes

• InsecureNodeFetch.ts: Added SOCKS5 proxy agent with TLS preservation

  • Custom SocksProxyAgentWithTls class to maintain TLS options
  • Agent caching for performance
  • Destination-based proxy routing (Bootstrap Only support)
  • Increased timeout for SOCKS connections (30s)

• SeedNodeAPI.ts: Updated to use proxy for seed node connections

  • Marks requests as FetchDestination.SEED_NODE
  • Increased timeout when proxy enabled

• ProxySettingsPage.tsx: New settings page for proxy configuration

  • Input validation (host required, port 1-65535)
  • Bootstrap Only toggle
  • Save/apply functionality

• settings-key.ts: New setting keys for proxy configuration

  • proxyEnabled, proxyHost, proxyPort
  • proxyUsername, proxyPassword
  • proxyBootstrapOnly

Localization

• English and Russian translations added
• Clear descriptions for Bootstrap Only mode

Testing

Tested with:

• ✅ Tor SOCKS5 proxy (localhost:9050)
• ✅ Authenticated SOCKS5 proxies
• ✅ Bootstrap Only mode (proxy for seed nodes, direct for service nodes)
• ✅ Full proxy mode (all traffic through proxy)
• ✅ TLS certificate pinning through proxy
• ✅ Auto-updater disabled when proxy enabled (security measure)

Build Artifacts

All platform builds verified:

• Linux: deb, rpm, AppImage, freebsd
• Windows: x64 installer
• macOS: arm64 and x64 (dmg + zip)

Build artifacts available at: https://github.com/scrense-hash/session-desktop/actions/runs/20681144343

Use Cases

1. Bypass Network Blocks: Route traffic through SOCKS5 proxy to access Session network in restricted regions
2. DPI Circumvention: Encrypted SOCKS tunnel prevents Deep Packet Inspection
3. Bootstrap Only: Use proxy only for initial connection, then direct P2P for better performance
4. Corporate Networks: Use existing SOCKS5 infrastructure for Session traffic

Breaking Changes

None. This is a purely additive feature with no impact on existing functionality when disabled.

Related Issues

Addresses requests for proxy support in Session Desktop to improve accessibility in restricted network environments.