feat: support installed guests and distribution display defaults

tests/test_profiles.py

@@ -33,9 +33,7 @@ class ProfilesTests(unittest.TestCase):
                 with self.subTest(field=field, value=value), self.assertRaises(ValueError):
                     Profile('guest', self.iso, **{field: value})
 
-    def test_missing_iso_and_duplicate_profile_preserve_existing(self):
-        with self.assertRaises(ValueError):
-            Profile('guest', self.root / 'missing.iso')
+    def test_duplicate_profile_preserves_existing(self):
         dest = self.root / 'guest.toml'
         save_profile(dest, Profile('guest', self.iso))
         original = dest.read_bytes()
@@ -43,6 +41,25 @@ class ProfilesTests(unittest.TestCase):
             save_profile(dest, Profile('guest', self.iso, memory=8192))
         self.assertEqual(dest.read_bytes(), original)
 
+    def test_disk_only_profile_roundtrips_without_media(self):
+        dest = self.root / 'guest.toml'
+        save_profile(dest, Profile('guest'))
+        self.assertIsNone(load_profile(dest).iso)
+        self.assertNotIn('iso =', dest.read_text())
+
+    def test_missing_media_does_not_block_loading_profile(self):
+        dest = self.root / 'guest.toml'
+        save_profile(dest, Profile('guest', self.iso))
+        self.iso.unlink()
+        self.assertEqual(load_profile(dest).iso, self.iso)
+
+    def test_display_bounds_and_types(self):
+        for field, values in {'width': (0, True, 16385), 'height': (0, '1080', 16385),
+                              'refresh_millihz': (-1, True, 1000001)}.items():
+            for value in values:
+                with self.subTest(field=field, value=value), self.assertRaises(ValueError):
+                    Profile('guest', self.iso, **{field: value})
+
     def test_profile_name_must_match_filename(self):
         path = self.root / 'guest.toml'
         path.write_text(f'name = "other"\niso = "{self.iso}"\n')