[Vardhman Gupta (Kaap10)]

Description

PathTraversalOutputScorer detects path traversal payloads aimed at sensitive files. Currently, its default pattern requires windows/system32 for Windows targets, missing:

1. windows/win.ini: The universally recognized, canonical proof-of-concept target on Windows across web security scanners, CTFs, and OWASP testing guides.
2. web.config: The root configuration file on IIS / ASP.NET holding database connection strings, machine keys, and app secrets.

This PR adds:

• windows{_SEPARATOR}win{_DOT}ini and web{_DOT}config into the {_FILE_END}-guarded sensitive file alternation.
• Support for forward slashes, backslashes, literal dots, URL-encoded dots (%2e), and double-encoded dots (%252e).
• Strict {_FILE_END} boundary checking, ensuring zero false positives on backup or extended files (win.ini.bak, web.config.old).

Fixes #3487

Tests and Documentation

• Added positive unit tests in tests/unit/score/regex/test_path_traversal_output_scorer.py covering win.ini and web.config across forward slashes, backslashes, and encoded dots.
• Added parameterized sentence-ending period test cases verifying ., . Then continue., .\n, and .\r\n endings.
• Added negative unit tests verifying that single traversal walks (../web.config, ../windows/win.ini), backup extensions (.bak, .old), and extended filenames are rejected.
• All 93 unit tests passing cleanly.
• Code style verified with ruff check and ruff format.