Pamac and pacman believes that I have no packages installed

[D.Dave]

I would replace pamac-gtk (the Gtk 4 version) with pamac-gtk3, so I’ve go using: sudo pacman -Rdd pamac-gtk && sudo pacman -S pamac-gtk3 but I got:
error: target not found: pamac-gtk.

Furthermore, if I execute pacman -Qo /usr/bin/pamac-installer (the file exists) I got error: No package owns /usr/bin/pamac-installer.
Is like that my system no longer see pamac installed, or worse. Because if, e.g I execute pacman -Qo /bin/firefox I again got: error: No package owns /bin/firefox.

EDIT:
On ANY file I got the error error: No package owns.

EDIT 2:

pacman --query --list

reports nothing, as if I don’t have any package installed!

EDIT 3:

Also in Pamac GUI, nothing is listed under “Installed”:

[Takakage]

Just to gather some information

ls -lh /var/lib/pacman /var/tmp/pamac/dbs

[D.Dave]

@Takakage

ls -lh /var/lib/pacman /var/tmp/pamac/dbs

/var/lib/pacman:
total 8,0K
drwxr-xr-x 2 root root 4,0K 25 ago 12.25 local
drwxr-xr-x 2 root root 4,0K 25 ago 18.56 sync

/var/tmp/pamac/dbs:
total 0
lrwxrwxrwx 1 dave dave  21 25 ago 18.56 local -> /var/lib/pacman/local
drwxrwxrwx 2 dave dave 200 25 ago 18.56 sync

[Takakage]

I claim no expertise here, but it looks like /var/lib/pacman/local is empty. Maybe this could help?
https://wiki.archlinux.org/title/Pacman/Restore_local_database

[D.Dave]

@Takakage

looks like /var/lib/pacman/local is empty

Is not empty; there is '/var/lib/pacman/local/ALPM_DB_VERSION'

[Takakage]

In addition to that file, the directory should contain subdirectories for every installed package. Mine contains 1,509 subdirectories.

[D.Dave]

I restored a Timeshift backup and everything is back to normal.