LeetCode 1268: Search Suggestions System

## [LeetCode 1268: Search Suggestions System](https://leetcode.com/problems/search-suggestions-system/)

**Difficulty:** Medium
**Category:** Trie

### Tasks
- [ ] Implement solution in `src/trie/search_suggestions_system.py`
- [ ] Verify tests pass: `pytest tests/test_search_suggestions_system.py`
- [ ] Analyze time and space complexity