[BUG] Missing StartupWMClass in setup-desktop-entry.sh causes generic icon when running in task bar

[heldderarbeit]

Describe the bug
A clear and concise description of what the bug is.

The setup-desktop-entry.sh script does not set a StartupWMClass entry. Therefore when launching Flashpoint from the desktop file, only a generic icon is shown in the taskbar instead of the flashpoint logo.

To Reproduce
Steps to reproduce the behavior:

1. Download and extract https://download.unstable.life/upload/fp14.0.1_lin_main_20250222.7z
2. Run setup-desktop-entry.sh
3. Copy the created desktop file to ~/.local/share/applications
4. Run flashpoint from the app launcher and look at the task bar

Expected behavior
flashpoint logo instead of generic logo should be shown in the task bar.
setup-desktop-entry.sh should create a StartupWMClass=flashpoint-launcher line

Screenshots
Before setting StartupWMClass=flashpoint-launcher:

After setting StartupWMClass=flashpoint-launcher:

Desktop (please complete the following information):

• OS: Linux
• Flashpoint Version: 14.0.1 (20250222)
• Log text (if relevant)

Additional context
This is a known problem for many programs, see for example: https://discussion.fedoraproject.org/t/app-icon-image-not-displaying-in-dock/130680

[Maoijoon]

This is not a launcher bug; the desktop entry and script that creates it are not a part of this repo. It's a problem with the Linux version itself.
I use a compositor that doesn't have a dock, and didn't show window icons by default until recently. I never got around to testing if the icon worked because of that, other than it showing up in my file manager.
Will test this fix to see if it works on my compositor now before applying it.

[Maoijoon]

Fixed both issues by using a standard SVG for the icon, adding StartupWMClass to the desktop entry, and creating the entry in ~/.local/share/applications by default. The XDG docs don't make it clear that entries need to be in a location like that for the icon to work; I had to figure that out myself. The entry's location can be changed if desired by editing the DIR variable in the script and re-running it.
Resolves this issue and #466.
setup-desktop-entry.sh