appActions() leaves out actions without text, but launchAppAction()
looked the QML menu row index up in the unfiltered KService::actions(),
so a text-less action ahead of the others made the context menu start
the wrong action. Pass the action name instead and resolve it with the
new ServiceAction::find(), covered by a test that builds a KService
from a temporary .desktop file whose first action has no name.

Backport of 3d03cbf from main (which resolves through AppActionId).

AppModel lists what the XDG menu places. Plasma's menu file places apps
without any Categories= entry in a "Lost & Found" catch-all, but a menu
without one leaves them out, and so does a menu entry removed with the
menu editor. Brave/Chromium webapps write no categories, so on such a
system a favourited webapp was missing from the alphabetically sorted
favourites (the app list filtered to favourites) and could not be
launched by storage id from the manual-order view either.

Kickoff resolves favourites through KService rather than the menu, so
do the same: AppFilterModel hands the favourites to AppModel, which also
serves the ones the menu left out, flagged OutsideMenuRole. The filter
model shows those rows only among the favourites, and they add no
category, so the grid and the category bar still follow the menu.
AppModel reloads only when the set of such favourites changes.

The drag handler moved stored favourites by rows of whatever the grid
showed. With "sort favourites alphabetically" on, or on the All tab and
the categories, dragging an app that is a favourite therefore moved a
different entry in the KActivities favourites, quietly scrambling the
manual order. Reorder only while the favourites tab shows the
KActivities model itself; adding an app from another tab is unchanged.

Backported from 4d2e951 on main.

(cherry picked from commit 3f914e2)

Any app whose .desktop path contained "snap" counted as a Snap and any
Exec line containing "flatpak" as a Flatpak, so distro packages such as
limine-snapper-restore and Discover's own Snap and Flatpak helper entries
showed the wrong source badge and "Manage in Discover" picked the wrong
backend. Match the export dirs (/flatpak/exports/, /snapd/desktop/) and
"flatpak run" / "/snap/" in the Exec line instead.

"Manage in Discover" also never saw the installed path: it passed the
absolute entry path to QStandardPaths::locate, which returns nothing for
an absolute path. Both now read the service through installSourceOf().

Checked against all 382 apps on a test system: only those three entries
change, to System. Unlike main, the X-Flatpak key is not used: distro
packages ship upstream's .desktop file with it (Podman Desktop).

Backported from 1252fad on main.

isNewer() compared the pre-release part as plain text, so 2.0.0-rc.10
ranked below 2.0.0-rc.9 and dev.100 below dev.99: a dev or RC user past
the ninth build was told an older build is an update, or missed a newer
one. Compare the dot-separated identifiers per SemVer instead (numeric
ones as numbers and below alphanumeric ones, a prefix ranks lower), and
the trailing number of same-prefix identifiers numerically too, for the
dot-less rc1/rc2 tags of older releases.

(cherry picked from commit fa0309a)

#205)

The panel height reserved a fixed header estimate that includes the
category bar and its two dividers. With the bar off those items take no
space in the layout, so their share went to the grid, which then showed
part of an extra row (6.40 rows for 6 configured). Take the category bar
block out of the estimate while the bar is hidden. With the bar shown
the size is unchanged.

Covered by tst_GridPanel for the centred window and the panel popup.

d51d3df took the category bar out of the panel height whenever the bar
was hidden, but it also hides while searching, in a prefix mode and in
the empty compact state, so the window shrank as soon as the user
typed. Key it to the "show category bar" setting instead: the panel
keeps its size while searching, as before, and with the bar turned off
the grid still shows the configured rows (#205).

Covered by tst_GridPanel: the height while searching, with the bar on
and off, in the centred window and the panel popup.

Each recents tile read its app through a binding over
appsModel.getByStorageId(id). A binding over a call only re-runs when
its arguments change, so when an app was uninstalled the app list
reloaded but the tile kept the old name and icon (and launched
nothing) until the recents changed or plasmashell restarted. Re-read
the tiles whenever the app model resets.

Covered by tst_RecentAppsHeader with a stub that, like the C++ model,
changes its app list without a change signal.