Add system-wide installation via pkexec with polkit policy

src/core/database.rs

@@ -1778,6 +1778,14 @@ impl Database {
         Ok(())
     }
 
+    pub fn set_system_wide(&self, id: i64, system_wide: bool) -> SqlResult<()> {
+        self.conn.execute(
+            "UPDATE appimages SET system_wide = ?2 WHERE id = ?1",
+            params![id, system_wide as i32],
+        )?;
+        Ok(())
+    }
+
     // --- Launch statistics ---
 
     pub fn get_top_launched(&self, limit: i32) -> SqlResult<Vec<(String, u64)>> {