id(ssh): use the alternate screen for raw interactive SSH sessions #545

What and why

Wrap interactive sessions in \x1b[?1049h/l so game repaints do not pile cleared frames into scrollback. REF wrongly claims this is already on main; RPT corrects it. Every view is a primary-screen clear and repaint, so game repaints pile cleared frames into the user's scrollback. The reference report wrongly says this is already on main.

Source

• RPT §5 'Three things that get conflated'
• RPT §5 Recommendation 1
• RPT §11 correction 6
• REF:168

RPT = doc/2026-10-18T18-40-00Z_report_platform_world_state/2026-10-18T18-40-00Z_report_platform_world_state.md, REF = doc/2026-10-18T00-00-00Z_reference_platform_state/2026-10-18T00-00-00Z_reference_platform_state.md. Both are uncommitted reports in the platform-world-apps-migration worktree.

Current status

Not started. grep -rn '1049' pkgs/id/src finds nothing; every view is a primary-screen clear and repaint, \x1b[H\x1b[2J (pkgs/id/src/world_presentation.rs:370, pkgs/id/src/world_ssh.rs:545/:550).

Acceptance criteria

• Raw interactive sessions send \x1b[?1049h on start and \x1b[?1049l on every exit path (quit, disconnect, error)
• Command (line) mode is unchanged
• A test asserts the enter and leave sequences
• Scrollback no longer collects cleared frames (checked by hand in a terminal)

Size

S

Prerequisites

None.