fix: derive prompt author from git config instead of log to handle empty emails

bin/create-prompt

@@ -12,11 +12,19 @@ create-prompt() {
     local repo_path="${2:-.}"
     local prompt_file="$repo_path/prompt.md"
 
-    local git_author
-    git_author="$(git log --format="%an <%ae>" -1 2>/dev/null || echo '')"
+    local git_author git_email
+    git_author="$(git config --get user.name 2>/dev/null || echo '')"
+    git_email="$(git config --get user.email 2>/dev/null || echo '')"
 
     export PROMPT_TITLE="$title"
-    export PROMPT_AUTHOR="${git_author:-}"
+
+    local prompt_author
+    if [[ -n "$git_email" ]]; then
+        prompt_author="${git_author} <${git_email}>"
+    else
+        prompt_author="$git_author"
+    fi
+    export PROMPT_AUTHOR="$prompt_author"
 
     envsubst < "$HOME/taskfile.build/prompt.md.template" > "$prompt_file"