[python] Optimise Architecture of App

[hayat01sh1da]

1. Overview

This PR mirrors the Ruby-side documentation change into the python/ project.
The Ruby tests received one-line class documentation comments (to satisfy Style/Documentation without a config patch); the pytest suites are function-based, so the idiomatic equivalent — a one-line module docstring — was added to each of the six test modules.

2. Key Changes & Differences

File	Before	After	Changes & Differences
python/calculator_cli_app/test/test_application.py	No module docstring	"""Tests the calculator CLI application entry point."""	Docstring added.
python/calculator_cli_app/test/queries/test_calculation_query.py	No module docstring	"""Tests the query that performs the arithmetic for the calculator CLI app."""	Docstring added.
python/fibonacci_sequence/test/test_application.py	No module docstring	"""Tests the Fibonacci sequence generator."""	Docstring added.
python/fizzbuzz/test/test_application.py	No module docstring	"""Tests every FizzBuzz implementation variant."""	Docstring added.
python/letter_matching_inspection/test/test_application.py	No module docstring	"""Tests the letter-matching inspection application."""	Docstring added.
python/nabeatsu/test/test_application.py	No module docstring	"""Tests every Nabeatsu implementation variant."""	Docstring added.

3. Summary

Documentation-only change; no runtime behaviour is affected.
Verified in WSL (Python 3.14.6 / pytest 9.0.3): all five sub-app suites pass (14 tests total).

Branch commits (newest first):

• 683ec17 Add module docstrings to test suites

4. References

• PEP 257 — Docstring Conventions
• [ruby] Optimise Architecture of App #124

[hayat01sh1da]