Desktop entry files Corelet under Internet, not Accessories #33

Installed on the uConsole, Corelet lands under Internet in the launch menu; it should be under
Accessories. The uConsole's Raspberry Pi OS desktop builds its menu from the freedesktop main
categories — Network is rendered as "Internet", Utility as "Accessories" — and
etc/corelet.desktop:9 declares Categories=Network;Chat;InstantMessaging;, so the menu is doing
exactly what the entry asks for. The file is installed to share/applications by
CMakeLists.txt:142 and ships in both .debs; the macOS bundle doesn't read it and is unaffected.

Why it matters: the menu is how the app is launched on the device, and Internet on a handheld with
a LoRa radio is where the browser lives, not where a mesh client is looked for. It is one line, but
it is one line every uConsole user hits before they ever see the UI.

The wrinkle is that Chat and InstantMessaging are additional categories that the spec says
require Network to also be present, so the two plausible fixes trade off against each other:

• Categories=Utility;Network;Chat;InstantMessaging; — validator-clean and keeps the semantic
  tags, but menu implementations file an entry under every matching main category, so it would
  then appear under both Accessories and Internet.
• Categories=Utility; — Accessories only, which is what was asked for, at the cost of
  desktop-file-validate complaining about the dropped Network if the tags are kept, or of
  losing Chat/InstantMessaging entirely if they are not.

Preference is Accessories alone unless a duplicate entry turns out to be harmless in practice.

Tasks

• Decide between Utility; alone and Utility;Network;Chat;InstantMessaging;, on the basis of
  what the uConsole menu actually does with two main categories
• Update Categories= in etc/corelet.desktop
• Run desktop-file-validate etc/corelet.desktop and keep it clean (or record why a warning is
  accepted)
• Verify on the device: install the rebuilt .deb, refresh the menu cache
  (update-desktop-database, then restart the panel) and confirm the entry sits under
  Accessories and nowhere else unintended