chore(audit): final Phase B batch — close out unused? cluster

Pillar 3 Phase B, batch 4 (final). Triages the last 13 `unused?` rows:
five deletes and eight SKILL.md surfacings.

Deleted (no callers anywhere, work duplicated inline or marginal value):
- `nomarchy-restart-hyprctl` and `nomarchy-restart-mako`: stale comments
  claimed "used by theme switching" but no Nomarchy script calls them.
  Theme-set and refresh paths call `hyprctl reload` / `makoctl reload`
  directly (see nomarchy-refresh-hyprland).
- `nomarchy-restart-tmux`: 3-line pgrep+source-file wrapper. Users can
  `tmux source-file ~/.config/tmux/tmux.conf` themselves.
- `nomarchy-battery-present`: the battery monitor reads
  `/sys/class/power_supply/BAT*` inline; the helper never got wired in.
- `nomarchy-sudo-keepalive`: intended to be `source`d from longer-running
  scripts (nomarchy-update, etc.) but nothing sources it. Resurrect from
  git history if a future caller actually needs it.

Surfaced in SKILL.md (now tagged `kept` by the audit):
- Themes: `nomarchy-theme-{remove,refresh,bg-install}`
- System: `nomarchy-sudo-{passwordless-toggle,reset}`,
  `nomarchy-restart-trackpad` (intel_quicki2c THC reload — a real laptop
  bug fix worth documenting)
- New Virtualization section: `nomarchy-windows-vm {install,launch,stop,status}`
- Enriched Troubleshooting's generic `nomarchy-refresh-<app>` example with
  literal `nomarchy-refresh-fastfetch` so the audit catches it.

Verified `nix flake check --no-build` still passes and zero callers
reference the deleted scripts.

**Phase B is now complete.** Final audit state: 164 → 159 scripts, all
tagged `kept`, `unused?` = 0, missing references = 0. The audit table is
now a clean reference of what Nomarchy ships, not a triage backlog.
Logged in `docs/ROADMAP.md` Shipped.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

core/system/scripts/nomarchy-battery-present

@@ -1,14 +0,0 @@
-#!/bin/bash
-set -e
-
-# Returns true if a battery is present on the system.
-# Used by the battery monitor and other battery-related checks.
-
-for bat in /sys/class/power_supply/BAT*; do
-  [[ -r $bat/present ]] &&
-  [[ $(cat $bat/present) == "1" ]] &&
-  [[ $(cat $bat/type) == "Battery" ]] &&
-  exit 0
-done
-
-exit 1

core/system/scripts/nomarchy-sudo-keepalive

@@ -1,11 +0,0 @@
-#!/bin/bash
-set -e
-
-# Prompt for sudo once and keep the credential alive in the background.
-# Source this script so the trap applies to the calling shell:
-#   source nomarchy-sudo-keepalive
-
-sudo -v
-while true; do sudo -n true; sleep 60; done 2>/dev/null &
-SUDO_KEEPALIVE_PID=$!
-trap "kill $SUDO_KEEPALIVE_PID 2>/dev/null" EXIT