v2.0.0 — Cross-platform daemon, proxy support, drag-drop keys, async health UI

Breaking changes

• Daemon C code rewritten with #ifdef _WIN32 cross-platform support
• profiles.json: new optional proxy field per server

New features

Cross-platform Windows support

• Native Windows daemon via CreateProcess + CreateThread + TCP IPC
• Auto-assigned localhost port, stored in ~/.sshc/daemon.port
• POSIX path uses posix_spawnp for macOS-optimized process creation
• Single source file compiles on both platforms (cc / cl / mingw)

Per-server proxy support

• Optional proxy field in profiles.json (ProxyCommand string)
• Web UI: modal with type dropdown (HTTP / SOCKS5 / SOCKS4 / Custom)
• CLI: sshc add --proxy "..." flag
• API: PUT /api/profiles/<name> {"proxy": "..."} / {"proxy": null}
• Proxy injected into all SSH invocations (health, exec, ensure_master, check)

Web UI overhaul

• Drag-and-drop key file upload (FileReader + base64, stored to ~/.sshc/keys/)
• Async parallel health checks — table renders instantly, status streams in
• Proxy configuration modal per server (dropdown + host/port + live preview)
• HTML-escaped rendering (XSS safe)
• Path traversal fix (os.path.basename on uploaded filenames)

Bug fixes

• Fix cmd_add flag parsing (positional args after flags)
• Fix cmd_remove None → '' for clean JSON output
• Fix cmd_profiles: use stdin pipe instead of fragile string interpolation
• Remove dead code (fd_is_socket, INVALID_SOCK, SOCKERR, HOME_ENV)
• Fix Windows ensure_master timeout 15s → 10s
• Fix /dev/null vs nul cross-platform in ssh_check and cleanup_masters
• Fix double close(cli) on fork failure
• Guard <unistd.h> for MSVC compatibility, add ssize_t typedef for Windows

Documentation

• SKILL.md: comprehensive agent workflow guide, proxy types table, platform notes
• README: agent-first narrative with /sshc slash command examples