Fix SC2155 violations in theme files

Separate local variable declarations from command substitution assignments
to avoid masking return values, per shellcheck SC2155.

Modified files:
- themes/mbriggs/mbriggs.theme.bash (2 fixes)
- themes/powerline-plain/powerline-plain.base.bash (1 fix)
- themes/sirup/sirup.theme.bash (2 fixes)
- themes/slick/slick.theme.bash (2 fixes)
- themes/zork/zork.theme.bash (2 fixes)

Total: 9 SC2155 violations fixed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: Ira Abramov

themes/mbriggs/mbriggs.theme.bash

@@ -21,11 +21,13 @@ function git_short_sha() {
 
 function prompt() {
 	local return_status=""
-	local ruby="${red?}$(ruby_version_prompt)${reset_color?}"
+	local ruby
+	ruby="${red?}$(ruby_version_prompt)${reset_color?}"
 	local user_host="${green?}\h${reset_color?}"
 	local current_path="\w"
 	local n_commands="\!"
-	local git_branch="$(git_short_sha)$(scm_prompt_info)"
+	local git_branch
+	git_branch="$(git_short_sha)$(scm_prompt_info)"
 	local prompt_symbol='λ'
 	local open='('
 	local close=')'

themes/powerline-plain/powerline-plain.base.bash

@@ -42,7 +42,8 @@ function __powerline_prompt_command {
 
 	## left prompt ##
 	for segment in $POWERLINE_PROMPT; do
-		local info="$(__powerline_${segment}_prompt)"
+		local info
+		info="$(__powerline_${segment}_prompt)"
 		[[ -n "${info}" ]] && __powerline_left_segment "${info}"
 	done
 

themes/sirup/sirup.theme.bash

@@ -5,10 +5,12 @@
 GIT_PS1_SHOWDIRTYSTATE="enabled"
 
 function rvm_version_prompt {
-	local gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
+	local gemset
+	gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
 
 	[ "$gemset" != "" ] && gemset="@$gemset"
-	local version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
+	local version
+	version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
 
 	[ "$version" == "1.9.2" ] && version=""
 

themes/slick/slick.theme.bash

@@ -25,9 +25,11 @@ esac
 PS3=">> "
 
 __my_rvm_ruby_version() {
-	local gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
+	local gemset
+	gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
 	[ "$gemset" != "" ] && gemset="@$gemset"
-	local version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
+	local version
+	version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
 	local full="$version$gemset"
 	[ "$full" != "" ] && echo "[$full]"
 }

themes/zork/zork.theme.bash

@@ -25,9 +25,11 @@ esac
 PS3=">> "
 
 __my_rvm_ruby_version() {
-	local gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
+	local gemset
+	gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
 	[ "$gemset" != "" ] && gemset="@$gemset"
-	local version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
+	local version
+	version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
 	local full="$version$gemset"
 	[ "$full" != "" ] && echo "[$full]"
 }