Update branding

Update the Ferese symbols, appearance-specific wallpapers, and rounded wallpaper and theme previews. Bundle Figtree and add the Ferese name to the website header.

Verified configuration, theme, Settings, wallpaper and installer tests, both UI renderers, the static site build, and browser layouts.

scripts/tests/test_portal_install.py

@@ -127,6 +127,31 @@ m.main()
         self.assertEqual(os.readlink(self.base / 'previous'), 'releases/second')
         self.assertEqual([(self.root / path).read_bytes() for path in (PORTAL, UNIT, DESKTOP)], first)
 
+    def test_upgrade_and_rollback_accept_retired_wallpaper_svg_with_verified_checksum(self):
+        legacy = Path(self.temporary.name) / 'legacy'
+        shutil.copytree(self.bundles[0], legacy)
+        svg = legacy / 'wallpapers/ferese.svg'
+        svg.write_text('<svg xmlns="http://www.w3.org/2000/svg"/>\n')
+        svg.chmod(0o644)
+        manifest_path = legacy / 'manifest.json'
+        manifest = json.loads(manifest_path.read_text())
+        manifest['files'].append({'target': 'wallpapers/ferese.svg', 'mode': '0644',
+                                  'sha256': installer.digest(svg)})
+        manifest_path.write_text(json.dumps(manifest))
+
+        self.run_command('install', legacy)
+        self.assertTrue((self.base / 'current/wallpapers/ferese.svg').is_file())
+        self.install(1)
+        self.assertEqual(os.readlink(self.base / 'current'), 'releases/second')
+        self.assertFalse((self.base / 'current/wallpapers/ferese.svg').exists())
+        self.run_command('rollback')
+        self.assertEqual(os.readlink(self.base / 'current'), 'releases/first')
+        self.assertEqual((self.base / 'current/wallpapers/ferese.svg').read_bytes(), svg.read_bytes())
+
+        svg.write_text('corrupt legacy wallpaper')
+        with self.assertRaisesRegex(ValueError, 'Checksum mismatch: wallpapers/ferese.svg'):
+            installer.validate_bundle(legacy)
+
     def test_upgrade_uses_previous_installer_ownership_receipts(self):
         self.install()
         release = self.base / 'releases/first'