chore: Enforce a few house rules via eslint (#2539)

scripts/deployment-update-symlink.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# `yarn deployment-update` — point the manual-test Home Assistant instance at
+# `yarn deployment-update` -- point the manual-test Home Assistant instance at
 # this worktree.
 #
 # Repoints the `$ACC_LIVE_LINK` symlink (the dev static server's document root)
@@ -9,7 +9,7 @@
 set -euo pipefail
 
 if [[ -z "${ACC_LIVE_LINK:-}" ]]; then
-  echo "ACC_LIVE_LINK is not set — point it at the symlink to update." >&2
+  echo "ACC_LIVE_LINK is not set -- point it at the symlink to update." >&2
   exit 1
 fi
 
@@ -18,4 +18,4 @@ mkdir -p "$(dirname "$ACC_LIVE_LINK")"
 ln -sfn "$TARGET" "$ACC_LIVE_LINK"
 
 echo "Advanced Camera Card → $TARGET"
-[[ -d "$TARGET" ]] || echo "(no dist/ here yet — run \`yarn start\` to build it)"
+[[ -d "$TARGET" ]] || echo "(no dist/ here yet -- run \`yarn start\` to build it)"