Group Anagrams by Frequency Signature

Given an array of strings `strs`, group the **anagrams** together. You can return the answer in any order. An **Anagram** is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. ### Constraints - `1 <= strs.length <= 10^4` - `0 <= strs[i].length <= 100` - `strs[i]` consists of lowercase English letters. ### Input Format A single line of space-separated strings. ### Output Format Print the number of anagram groups formed, followed by each group's count and words sorted lexicographically. For canonical grading across languages, return a list of lists of strings where groups are sorted by the first word in each group.