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

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.backends._legacy:_Backend"
 
 [project]
 name = "simtrace2-pysniff"
-version = "1.22.7"
+version = "1.22.8"
 description = "Python-based sniffing tool for SIMtrace2 hardware (SIM card communication sniffer)"
 readme = {file = "README.md", content-type = "text/markdown"}
 license = {text = "GPL-2.0-or-later"}