style: Normalize variable expansions to ${var} across the repo

Replace bare $var with ${var} everywhere it was still used, matching
the convention already established in rc.d/prompt and rc.d/history.
Positional parameters ($1, $@, $#) and special variables ($?, $$, $-)
are left as-is, consistent with existing usage in _helpers.bash.

rc.d/broot is auto-generated by the broot binary and will likely be
overwritten with its original formatting on the next broot update.

libs/note.bash

@@ -1,17 +1,17 @@
 note() {
     # if file doesn't exist, create it
-    if [[ ! -f $HOME/.notes ]]; then
-        touch "$HOME"/.notes
+    if [[ ! -f "${HOME}/.notes" ]]; then
+        touch "${HOME}"/.notes
     fi
 
     if [[ $# -eq 0 ]]; then
         # no arguments, print file
-        cat "$HOME"/.notes
+        cat "${HOME}"/.notes
     elif [[ "$1" == "-c" ]]; then
         # clear file
-        echo "" >"$HOME"/.notes
+        echo "" >"${HOME}"/.notes
     else
         # add all arguments to file
-        echo "$@" >>"$HOME"/.notes
+        echo "$@" >>"${HOME}"/.notes
     fi
 }

libs/password.bash

@@ -1,21 +1,21 @@
 encpasswd() {
         local password_clear=$1
-        local password_md5hash=$(openssl passwd -1 "$password_clear")
-        local password_sha1=$(echo -n "$password_clear" | openssl dgst -sha1)
-        echo "Password : $password_clear"
-        echo "MD5HASH  : $password_md5hash"
-        echo "SHA1  : $password_sha1"
+        local password_md5hash=$(openssl passwd -1 "${password_clear}")
+        local password_sha1=$(echo -n "${password_clear}" | openssl dgst -sha1)
+        echo "Password : ${password_clear}"
+        echo "MD5HASH  : ${password_md5hash}"
+        echo "SHA1  : ${password_sha1}"
 }
 
 genpasswd() {
         local l=$1
-        [ "$l" == "" ] && l=12
+        [ "${l}" == "" ] && l=12
         local password_clear=$(tr -dc A-Za-z0-9_ </dev/urandom | head -c "${l}" | xargs)
-        local password_md5hash=$(openssl passwd -1 "$password_clear")
-        local password_sha1=$(echo -n "$password_clear" | openssl dgst -sha1)
-        local password_base64=$(echo -n "$password_clear" | base64)
-        echo "Password : $password_clear"
-        echo "Base64 : $password_base64"
-        echo "MD5HASH  : $password_md5hash"
-        echo "SHA1  : $password_sha1"
+        local password_md5hash=$(openssl passwd -1 "${password_clear}")
+        local password_sha1=$(echo -n "${password_clear}" | openssl dgst -sha1)
+        local password_base64=$(echo -n "${password_clear}" | base64)
+        echo "Password : ${password_clear}"
+        echo "Base64 : ${password_base64}"
+        echo "MD5HASH  : ${password_md5hash}"
+        echo "SHA1  : ${password_sha1}"
 }

libs/term.bash

@@ -1,5 +1,5 @@
 function term_change_title {
-	case $TERM in
+	case ${TERM} in
 	# Change the window title of X terminals
 	xterm* | rxvt* | urxvt* | Eterm)
 		echo -ne "\033]0;${1}\007"

libs/todo.bash

@@ -1,20 +1,20 @@
 todo() {
-    if [[ ! -f $HOME/.todo ]]; then
-        touch $HOME/.todo
+    if [[ ! -f "${HOME}/.todo" ]]; then
+        touch "${HOME}/.todo"
     fi
 
     if [[ $# -eq 0 ]]; then
-        cat $HOME/.todo
+        cat "${HOME}/.todo"
     elif [[ "$1" == "-l" ]]; then
-        cat -n $HOME/.todo
+        cat -n "${HOME}/.todo"
     elif [[ "$1" == "-c" ]]; then
-        echo "" > $HOME/.todo
+        echo "" > "${HOME}/.todo"
     elif [[ "$1" == "-r" ]]; then
-        cat -n $HOME/.todo
+        cat -n "${HOME}/.todo"
         echo -ne "----------------------------\nType a number to remove: "
         read NUMBER
-        sed -ie ${NUMBER}d $HOME/.todo
+        sed -ie "${NUMBER}d" "${HOME}/.todo"
     else
-        echo "$@" >> $HOME/.todo
+        echo "$@" >> "${HOME}/.todo"
     fi
 }