Add SmoothSort (Dijkstra’s adaptive in-place heapsort variant)

[GziXnine]

Checklist

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized it.
• All filenames are in PascalCase.
• All functions and variable names follow Java naming conventions.
• All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• All new algorithms include a corresponding test class that validates their functionality.
• All new code is formatted with clang-format -i --style=file path/to/your/file.java.

Summary

This Pull Request adds an implementation of Smooth Sort to the com.thealgorithms.sorts package. Smooth Sort is an adaptive, in-place sorting algorithm invented by Edsger W. Dijkstra (1981), designed to achieve near-linear performance on already sorted or nearly sorted inputs while maintaining an O(n log n) worst-case bound.

Features

• Adaptive behavior with improved performance on nearly sorted arrays
• In-place sorting with O(1) auxiliary space
• Handles edge cases (empty array, single-element array, sorted input, reverse sorted input, and random input)
• Implements SortAlgorithm consistently with existing sorting implementations

Implementation Details

• Uses Leonardo numbers to manage the sizes of heap-ordered Leonardo trees
• Core operations implemented:
  • sift: restores heap order within a Leonardo tree
  • trinkle: restores global heap order across the forest using the “stepson” relationship between roots
• Documentation follows the repository’s Javadoc conventions and includes reference links

Tests

• Adds SmoothSortTest extending the shared SortingAlgorithmTest suite
• Validates correctness across common scenarios used throughout the repository (including empty/singleton/duplicates/strings/random arrays)

Complexity

• Best Case: O(n)
• Average Case: O(n log n)
• Worst Case: O(n log n)
• Space: O(1) auxiliary space (in-place)

Closes #6632

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.98%. Comparing base (ca4bebc) to head (8bf1a0e).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7200      +/-   ##
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+ Coverage     78.89%   78.98%   +0.09%     
- Complexity     6880     6907      +27     
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  Files           774      775       +1     
  Lines         22746    22822      +76     
  Branches       4468     4482      +14     
============================================
+ Hits          17945    18027      +82     
+ Misses         4078     4076       -2     
+ Partials        723      719       -4     

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[DenizAltunkapan]

Thank you for your contribution @GziXnine