Add support for .pth files

> A path configuration file is a file whose name has the form **name.pth** and exists in one of the four directories mentioned above; its contents are additional items (one per line) to be added to sys.path. Non-existing items are never added to sys.path, and no check is made that the item refers to a directory rather than a file. No item is added to sys.path more than once. Blank lines and lines beginning with # are skipped. Lines starting with import (followed by space or tab) are executed.

https://docs.python.org/3/library/site.html

.pth files are often used by python packaging systems (like uv, etc...) to make working on the current project more elegant, by pointing from the .venv/ path to the project path.

Beginne mit der verlinkten Python-site-Dokumentation und der Behandlung des Pfads .venv/ durch componentize-py. Vergleiche das angeforderte Verhalten mit den .pth-Regeln für Pfadeinträge, Kommentare, leere Zeilen, doppelte Einträge, fehlende Pfade und Importzeilen. Erledigt bedeutet, dass unterstützte .pth-Dateien gültige Projektpfade zu sys.path hinzufügen können, ohne ungültige oder doppelte Einträge hinzuzufügen.

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