tui-installerlisted

# tui-installer Overhaul task 8 (installer half). Turns the recommendation in `recommendations/tui-for-agents.md` into a runnable, **ask-first** installer. Nothing installs unless the user opts in. ## Use ``` bash scripts/install-tui.sh --check # report what's installed vs missing bash scripts/install-tui.sh # dry-run: print the install plan, install NOTHING (default) bash scripts/install-tui.sh --apply # install missing tools, asking y/N per tool ``` The recommended stack (see the recommendation doc for why): **zellij** (multiplexer), **claude-squad** (agent orchestrator, git-worktree isolation), **lazygit** (diff review + staging), **delta** (highlighted diffs). Tools without a clean apt/cargo package (claude-squad, lazygit on some distros) are marked `MANUAL:` with the upstream install URL rather than a fabricated command. ## Onboarding behavior (task 8) When applying agent-harness to a machine, run `--check` and **ask the user whether to install** the missing TUI tools — never install unprompted. Re-check periodically (or when the recommendation doc changes) and ask again if a better tool appears; keep the tool list in sync with `recommendations/tui-for-agents.md`. ## Why dry-run default + fake-install seam Installing system tools is side-effectful, so the default only *plans*. The detection is testable without touching the system via `TUI_FAKE_INSTALLED="zellij delta"` (used by `test_install_tui.sh`, 11/11). The actual package installs are the on