fix(tui): restore Playbook menu after keyboard selection

[edwin-zvs]

Summary\n\n- preserve the pending Playbook selection menu between a zero-width C-Space mark and the movement key that makes the selection non-empty\n- add a TestBackend regression through top-level terminal key ingress and rendered frames\n- interleave real renders through the existing mouse Down, Drag, and Up regression\n- retain Tab focus, two-layer Escape, and the no-ghost rule when selection_menu is absent\n\n## Root cause\n\nThe selection-menu key handler runs before editor movement. C-Space created a zero-width mark with a pending menu, but the following movement key saw no non-empty range and cleared the menu before extending the mark. The renderer then correctly honored selection_menu == None, leaving visibly selected text with no action menu.\n\nMouse drag does not pass through that intermediate key-handler transition, so the archived mouse test remained green.\n\n## Web parity\n\nThe web Playbook derives selection from the browser DOM and only shows its menu for a non-collapsed DOM range. It has no analogous pending zero-width mark/menu state, so no web change is needed.\n\n## Verification\n\n- cargo test -p construct-cli --bin construct playbook: 356 passed\n- cargo test -p construct-e2e --test playbook_view: 8 passed\n- cargo build: passed\n- git diff --check: passed\n- full CLI suite: 1,442 passed; only the known environment-sensitive color::tests::truecolor_backend_still_emits_rgb baseline failed, matching PRs #1285 and #1286\n\nNo spec update: spec 0196 already requires a passive menu for a non-empty selection, Tab focus, two-stage Escape, and no ghost menu after dismissal.\n\nReviewer media is omitted because the frame-level regressions directly verify the transient passive, focused, dismissed, and mouse-drag frames.