[Feature] Android mobile app — dark amber-accent SSH client

[thangnm93]

Problem Statement

YourSSH ships only as a desktop app (macOS / Windows / Linux). There is no way to manage saved hosts, open SSH sessions, browse files over SFTP, or sync host data from a phone — so users cannot reach their servers while away from a desktop.

Proposed Solution

A dedicated Android phone UI (under app/lib/mobile/) that reuses the existing desktop providers and services (no business-logic duplication) behind a dark, Apple-inspired amber design. Nine screens:

• Hosts — searchable, tag-grouped host list with reachability/latency badges and an add-host FAB
• New host — grouped add/edit form (general / auth / advanced), Save & connect
• Terminal — live SSH session with session tabs, a shortcut/accessory key bar, pinch-zoom and cursor-drag gestures
• Files — SFTP browser (breadcrumb, typed icons, upload/download)
• Keys — SSH key management (generate / import, real SHA256 fingerprints)
• Snippets — saved commands, tap-to-run into the active session
• Port forwarding — local / remote / dynamic tunnels with start/stop
• Settings — terminal appearance, biometric lock, Supabase sync
• Sync / QR pairing — Supabase config + P2P QR transfer

Bottom tab bar: Hosts · Snippets · Keys · Settings. Preserves biometric app-lock, TOFU host-key verification, and P2P import. The amber accent is mobile-only; the desktop theme is untouched.

Alternatives Considered

• Responsive desktop layout on phones — the desktop multi-pane UI does not fit a phone; rejected.
• A separate / third-party SSH client — would not share YourSSH's host list, keys, and sync; rejected.

Additional Context

• Android phone form factor only (no tablet multi-pane in this pass; no RDP / VNC / plugins on mobile).
• Reuses HostProvider / SessionProvider / SshService / SyncService etc.
• Design imported from the Claude Design "SSH Client" project; spec & plan under docs/superpowers/.

[thangnm93]

Duplicate of #85 (tracked by PR #86). Closing.