feat(installer): review-then-edit loop with field-level re-prompt

Previously the review screen only offered Confirm/Abort, so a typo or
wrong-disk choice meant aborting the whole run and starting over (or
hand-editing /tmp/nomarchy-install.state.sh). On --resume the situation
was worse: every prompt re-runs (each short-circuits when its var is
set), the user lands on a review they can't change.

review_configuration() now offers Continue / Edit a field / Abort. Edit
opens a multi-select of every saved field; chosen fields clear and the
next loop iteration in main() re-prompts only those. The LUKS passphrase
short-circuits when already set, so editing other fields doesn't
re-prompt for it.

Net flow change:
- Fresh install: same prompts, then review with Edit option (typo fixes
  without restarting).
- --resume: state loads, every prompt skips (vars set), lands straight on
  review — exactly what the roadmap entry called for.

Verified via `bash -n`. Live VM dry-run not exercised in this session.

docs/ROADMAP.md

@@ -28,7 +28,6 @@ Guardrails (apply when adding anything):
 - **Gaming — declarative flathub remote.** `services.flatpak.enable` doesn't ship a declarative remote API in nixpkgs. Either add the `flatpak-managed-install` overlay, write a one-shot systemd unit that runs `flatpak remote-add --if-not-exists flathub …`, or surface the manual step in `nomarchy-welcome`.
 - **First-run welcome wizard.** Extend `nomarchy-welcome` from a one-shot greeter into a guided picker: theme, panel position, monospace font, "what's a sane home.nix to start with?". Runs once, persists "done" in `state.json`.
 - **Plymouth theme variants per palette.** Currently one Plymouth theme; could template per-palette so the boot splash matches the active theme.
-- **Installer pre-flight resume polish.** If the user Ctrl-Cs mid-install and runs `--resume`, re-show the review screen before re-prompting for any unsaved fields.
 
 ### Later (speculative or research-shaped)
 
@@ -124,6 +123,7 @@ Each PR description should reference the row(s) in `docs/SCRIPTS.md` it closes,
 
 (Move items here when they land — keep them brief, link the commit/PR.)
 
+- _2026-04-26_ — Installer review-then-edit flow (`installer/install.sh`). Review screen now offers Continue / Edit a field / Abort. Edit opens a multi-select of saved fields; chosen fields clear and the next loop iteration re-prompts only those. Benefits both fresh installs (typo fixes without abort+restart) and `--resume` (lands on review immediately, since the loaded vars short-circuit each prompt). LUKS passphrase is held in memory across loop iterations so re-edits don't re-ask for it.
 - _2026-04-26_ — `docs/TROUBLESHOOTING.md`. The five most common rebuild errors (option-already-declared, attribute-missing, Stylix target conflict, home-manager `.hm-bak` churn, impermanence path missing) with copy-paste fixes. Linked from `README.md` and `docs/MIGRATION.md`.
 - _2026-04-26_ — Gaming preset module (`core/system/gaming.nix`). Opt-in `nomarchy.system.gaming.enable` (default false). Wires `programs.steam` (with `remotePlay`/`localNetworkGameTransfers` firewall holes via `mkDefault`), `programs.gamemode`, and `services.flatpak`. Flathub remote and Hyprland window-rule split into separate Next-column rows.
 - _2026-04-26_ — Accessibility preset module (`core/system/accessibility.nix`). New `nomarchy.system.accessibility.{enable,cursorSize}` options (opt-in, default off — accessibility isn't a hardware-derived signal). Enables `services.gnome.at-spi2-core`, installs Orca, and sets `XCURSOR_SIZE=32` (configurable). Hyprland-side companion (key-repeat slowdown, Orca keybinding, high-contrast palette) split into a new Next-column row.