v0.3.4

What's new

• tether watch: stream live session output to your terminal
• tether new: create sessions from the CLI, with optional prompt and adapter
• No implicit claude_auto fallback: missing adapter now gives a clear error with instructions instead of silently using Claude
• tether init: simplified, no longer asks about agents
• README: rewritten to lead with the attach workflow (the primary path for most users)
• UX: per-session attach spinner, inline errors, permission dialog shows correct agent name, deny reason hidden until needed