Refactor version handling to dynamically retrieve from __init__.py in setup.py

[chigwell]

User Story
As a maintainer,
I want setup.py to dynamically retrieve the package version from __init__.py
so that version management is centralized and release processes avoid manual updates.

Background
The current setup.py (line 4) hardcodes an arbitrary version string (2025.4.231612), which:

• Requires manual updates for releases, increasing error risk
• Creates confusion for users seeing a nonsensical future version
• Complicates CI/CD pipelines due to lack of single source of truth

The solution involves:

1. Adding a __version__ attribute to folder_scanner/__init__.py
2. Modifying setup.py to parse this value dynamically

Risks include potential version-parsing failures during installation if not implemented cautiously.

Acceptance Criteria

• Add __version__ = "1.0.0" to folder_scanner/__init__.py
• Update setup.py to extract __version__ from __init__.py without importing the package (use file reading + regex)
• Remove hardcoded version= value from setup.py
• Validate by running python setup.py sdist and confirming the built package's metadata reflects the __version__ value
• Ensure the README's PyPI badge URL remains functional post-change (no version hardcoding in README.md)