Move Working Directory from System Temp to Application Data

[chchwy]

Currently, Pencil2D extracts .pclx files (literally a ZIP) to the system's temporary directory for working directory.

This could have two issues:

• Data loss: System cleanup tools or OS maintenance can delete temp files at any time, e.g., on restart, during disk cleanup, or third-party tools
• Recovery: working files in temp probably already gone after Pencil2D crashes.

Proposed Solution

Move the working directory to platform-specific application data directories QStandardPaths::AppLocalDataLocation

Platform	Location
Windows	C:\Users\username\AppData\Local\Pencil2D\
macOS	~/Library/Application Support/Pencil2D/
Linux	~/.local/share/Pencil2D/ (XDG_DATA_HOME)

Notes

• Working files always persist except someone explicitly cleans it up (Good for Crash recovery)
• AppData directories should always be writable
• Other people cannot access the personal AppData so it has better privacy