Say when the processor build landed instead of the Vulkan one

The install falls back to upstream's CPU archive whenever Dikte's own
release, the file in it, or its reviewed digest is not there, and until
the package is published by hand that is every download. It happened
without a word: the window said "Downloaded, version v1.9.3." either
way, and a graphics card sitting idle looks exactly like one being used.

The install record now carries which of the two builds landed, written
only where both were on offer, and the settings window says so on the
line that already reports the version.

dikte/settings_ui.py

@@ -358,6 +358,13 @@ class LocalModelBox(QGroupBox):
             # for this machine and may reach the graphics card, while the
             # released binaries carry processor backends only.
             self.program_label.setText(t("Installed on the system: {path}", path=path))
+        elif ggml.vulkan_missing(self.program):
+            # The download landed the processor build where the graphics card
+            # one belongs, and nothing else on this window would say so.
+            self.program_label.setText(
+                t("Downloaded, version {version}. There was no Vulkan build, "
+                  "so this one runs on the processor.",
+                  version=ggml.installed_version(self.program) or "?"))
         else:
             self.program_label.setText(
                 t("Downloaded, version {version}.",