Unify session action button styles: same padding, delete in red

- Add .session-copy CSS (was unstyled — browser default)
- .session-download/.session-copy: neutral gray, same padding 4px 12px
- .session-delete: red (--danger) instead of accent
- Bump 1.22.8, SW cache v39->v40

tests/test_pcap_import.py

@@ -224,7 +224,7 @@ class TestImportEndpoint(unittest.TestCase):
 class TestVersion(unittest.TestCase):
     def test_package_version(self):
         from simtrace2_pysniff import __version__
-        self.assertEqual(__version__, '1.22.7')
+        self.assertEqual(__version__, '1.22.8')
 
     def test_status_includes_version(self):
         import os