Changes in g-18 (ready for promotion)

• Fix "1" echo: Changed do_approval() from sending '1\r' to just '\r' — stops echoing "1" into Gemini's reply window
• Approval timing: Reduced pre/post-write delays from 0.5s to 0.1s
• Post-write sleep: Added post-write delay to keep in_approval set during UI transition (prevents re-trigger)
• Terminal size race fix: Read shutil.get_terminal_size() before _setup_console()
• Renamed: in_countdown -> in_approval for clarity

Promotion checklist

• Test g-18 with Gemini CLI (verify no "1" echo)
• Verify 0.1s timing works with Gemini's permission UI
• Add transcript save (port from c-19)
• Promote to production
• Close this issue